https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-of-equations-with-substitution/v/practice-using-substitution-for-systems 2021-06-21T15:29:06Z Systems of equations with substitution: -3x-4y=-2 & y=2x-5 Learn to solve the system of equations -3x - 4y = -2 and y = 2x - 5 using substitution. Sal Khan video https://cdn.kastatic.org/googleusercontent/628RjCJ_CsSqK0HqbIq8aNzgQ257wowuvmMVKKnUJmO9mpgtI2jeA2M8Zz15za_g4gB2lK1zv-A2gIIc8JNmvrKv Systems of equations with substitution: -3x-4y=-2 & y=2x-5 Learn to solve the system of equations -3x - 4y = -2 and y = 2x - 5 using substitution. https://cdn.kastatic.org/ka-youtube-converted/GWZKz4F9hWM.mp4/GWZKz4F9hWM.mp4 261 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-of-equations-with-substitution/a/substitution-method-review-systems-of-equations 2021-06-21T15:29:14Z Substitution method review (systems of equations) The substitution method is a technique for solving a system of equations. This article reviews the technique with multiple examples and some practice problems for you to try on your own. article https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-of-equations-with-substitution/e/systems_of_equations_with_substitution 2025-12-28T12:11:43.202987517Z Systems of equations with substitution Solve systems of equations where one of the equations is solved for one of the variables. Tomer Gal exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-elimination/v/simple-elimination-practice 2021-04-19T14:43:37Z Systems of equations with elimination: x-4y=-18 & -x+3y=11 Sal solves the following system of equations by eliminating x: x-4y=-18 and -x+3y=11. Sal Khan video https://cdn.kastatic.org/googleusercontent/d2DLGZYUCnN2rbaWWNiLKf7sMsIOEzLeMxjvB8VePoc29qHG-cvvnfdD6Agj2ILs1j3E1MCGU3OGfG7dOql900w Systems of equations with elimination: x-4y=-18 & -x+3y=11 Sal solves the following system of equations by eliminating x: x-4y=-18 and -x+3y=11. https://cdn.kastatic.org/ka-youtube-converted/NPXTkj75-AM.mp4/NPXTkj75-AM.mp4 359 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-elimination/a/elimination-method-review 2021-04-29T07:49:27Z Elimination method review (systems of linear equations) The elimination method is a technique for solving systems of linear equations. This article reviews the technique with examples and even gives you a chance to try the method yourself. article https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:solving-systems-elimination/e/systems_of_equations_with_elimination_0.5 2025-12-28T12:11:43.202987517Z Systems of equations with elimination Solve systems of equation with one-step elimination (e.g., x-values or y-values cancel each other out). Tomer Gal exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/v/inconsistent-systems-of-equations 2021-04-19T14:43:38Z Systems of equations number of solutions: fruit prices (1 of 2) Sal gives an example of a system of equations that has no solution! Sal Khan video https://cdn.kastatic.org/googleusercontent/966TVCMSq2me01GOkpmJfVXTQtwRJBxVxCQeO5g8zMv4tw21hkn2EfjHob5oOaIT56_1uH3LWADXXJiZsiLTp4FzMg Systems of equations number of solutions: fruit prices (1 of 2) Sal gives an example of a system of equations that has no solution! https://cdn.kastatic.org/ka-youtube-converted/NJRyxmommqQ.mp4/NJRyxmommqQ.mp4 565 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/v/infinite-solutions-to-systems 2021-04-19T14:43:38Z Systems of equations number of solutions: fruit prices (2 of 2) Sal gives an example of a system of equations that has infinite solutions! Sal Khan video https://cdn.kastatic.org/googleusercontent/N3hZWxNmgG-G_cqbpr7m9LnntVXeMW4hSiLmCD3_Pu2PPU6IDGv59T9kdl6BDHZLDCFIaXRsTSlwKY13SZQyuuMM9A Systems of equations number of solutions: fruit prices (2 of 2) Sal gives an example of a system of equations that has infinite solutions! https://cdn.kastatic.org/ka-youtube-converted/MpRUEGD2-_c.mp4/MpRUEGD2-_c.mp4 428 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/v/practice-thinking-about-number-of-solutions-to-systems 2021-02-07T17:14:01Z Number of solutions to a system of equations graphically Sal determines how many solutions the following system of equations has by considering its graph: 10x-2y=4 and 10x-2y=16. Sal Khan video https://cdn.kastatic.org/googleusercontent/LSPenQW1-1XWojpiiFK3oJpAy4UchBLSv3EjgjiP-nsEaT6i02-ntLjopewu763fNrdsLTi7lLULqHO0tqp9oWy08g Number of solutions to a system of equations graphically Sal determines how many solutions the following system of equations has by considering its graph: 10x-2y=4 and 10x-2y=16. https://cdn.kastatic.org/ka-youtube-converted/SuB1gkto9LU.mp4/SuB1gkto9LU.mp4 396 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/e/graphical-solutions-to-systems 2026-04-07T23:36:17.218592739Z Number of solutions to a system of equations graphically Determine the number of solutions of a given system of equations by considering its graph. Tomer Gal exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/v/examples-algebraically-analyzing-solutions-to-systems 2022-10-06T11:39:29.972393653Z Number of solutions to a system of equations algebraically Sal solves several examples where he reasons about the number of solutions of systems of equations using algebraic reasoning. video https://cdn.kastatic.org/ka_thumbnails_cache/518c64a9-c141-4ad9-a0da-40161c1df7ef_1280_720_base.png Number of solutions to a system of equations algebraically Sal solves several examples where he reasons about the number of solutions of systems of equations using algebraic reasoning. https://cdn.kastatic.org/ka-youtube-converted/ogEddosP1G8.mp4/ogEddosP1G8.mp4 361 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/a/number-of-solutions-to-system-of-equations-review 2022-04-27T20:03:03.137387157Z Number of solutions to system of equations review A system of linear equations usually has a single solution, but sometimes it can have no solution (parallel lines) or infinite solutions (same line). This article reviews all three cases. article https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:number-of-solutions-to-systems-of-equations/e/constructing-consistent-and-inconsistent-system 2026-03-10T04:30:37.966653692Z Number of solutions to a system of equations algebraically Determine the number of solutions of a given system of equations by considering its algebraic solution process. Tomer Gal exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:systems-of-equations-word-problems/v/ex-3-age-word-problem 2021-02-07T17:14:00Z Age word problem: Ben & William Sal solves the following age word problem: William is 4 times as old as Ben. 12 years ago, William was 7 times as old as Ben. How old is Ben now? Sal Khan video https://cdn.kastatic.org/googleusercontent/MYxSSU8heK6Iaq5yk3WIQnTwkQH8-mgmfDvEfccpVxxi64tlo3JlSbEBenA7tRVzuhBr8aJqtOH3V3S4MGjUUJQJ Age word problem: Ben & William Sal solves the following age word problem: William is 4 times as old as Ben. 12 years ago, William was 7 times as old as Ben. How old is Ben now? https://cdn.kastatic.org/ka-youtube-converted/RGbA2IyJILY.mp4/RGbA2IyJILY.mp4 388 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:systems-of-equations-word-problems/v/ex-1-age-word-problem 2021-02-07T17:14:00Z Age word problem: Arman & Diya Sal solves the following age word problem: Arman is 18. Diya is 2. How many years will it take for Arman to be 3 times as old as Diya? Sal Khan video https://cdn.kastatic.org/googleusercontent/N0lKi43uDDy6tY2gpiZUcvXKKgePhLF4Ay0B1ZY-m3gjRo-etb9j2WBH44U1dFOIXGIAIccqjyfBaOYUi5U_IsPY Age word problem: Arman & Diya Sal solves the following age word problem: Arman is 18. Diya is 2. How many years will it take for Arman to be 3 times as old as Diya? https://cdn.kastatic.org/ka-youtube-converted/W-5liMGKgHA.mp4/W-5liMGKgHA.mp4 321 Simultaneous linear equations https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:systems-of-equations/x2f8bb11595b61c86:systems-of-equations-word-problems/e/age_word_problems 2025-02-27T12:31:05.94748833Z Age word problems Solve age word problems with a system of equations. Ben Alpert exercise