https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:intro-variables/v/what-is-a-variable 2023-05-23T10:28:13.689545116Z What is a variable? Variables in math are symbols, often letters, that represent different values in various situations. They help us understand and solve problems with changing values. For example, when calculating total earnings at a job with an hourly wage plus tips, a variable can represent the fluctuating tips, making it easier to determine total income. Sal Khan video https://cdn.kastatic.org/googleusercontent/Z0Ew0H4CUDZ7Hc0NbhfLe904T2e_lMEyScP69jTH-2Kcauq4mxzwzwDS-yQlWeQlDKGfOS3-podwVZQRor01fOc What is a variable? Variables in math are symbols, often letters, that represent different values in various situations. They help us understand and solve problems with changing values. For example, when calculating total earnings at a job with an hourly wage plus tips, a variable can represent the fluctuating tips, making it easier to determine total income. https://cdn.kastatic.org/ka-youtube-converted/tHYis-DP0oU.mp4/tHYis-DP0oU.mp4 198 Algebraic manipulation https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:combine-like-terms/v/combining-like-terms-3 2024-03-14T20:05:09.2926958Z Combining like terms with negative coefficients This example of combining like terms in an expression gets a little hairy. Pay attention. Sal Khan video https://cdn.kastatic.org/googleusercontent/k29Rm6wottC6OetSa5iMH03tNLvk_2HuxiiJEqjxI-6IHoUit5UIVhTa8pSukscBwFnPazW-72Mz4clvGbyA1lVr Combining like terms with negative coefficients This example of combining like terms in an expression gets a little hairy. Pay attention. https://cdn.kastatic.org/ka-youtube-converted/FNnmseBlvaY.mp4/FNnmseBlvaY.mp4 279 Algebraic manipulation https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:combine-like-terms/e/combining_like_terms_1 2026-03-26T21:40:53.527314638Z Combining like terms with negative coefficients Simplify algebraic expressions by combining like terms. Coefficients on some terms are negative. Scott Menke exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:combine-like-terms/v/simplifying-expressions-involving-rational-numbers 2021-06-30T17:51:04Z Combining like terms with rational coefficients Learn how to rewrite algebraic expressions by combining like terms. The expressions in this video have decimal and fraction coefficients. video https://cdn.kastatic.org/googleusercontent/zGWEiNW5dHAogogvkzr1YYpKtJYQajeOpj91t9bFZ1VMaEmiZZgmASXdSmKnU7BZJVC1IRNWrGxlOp-D3Sf-JD4kgQ Combining like terms with rational coefficients Learn how to rewrite algebraic expressions by combining like terms. The expressions in this video have decimal and fraction coefficients. https://cdn.kastatic.org/ka-youtube-converted/rtNuo7R3scY.mp4/rtNuo7R3scY.mp4 256 Algebraic manipulation https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:foundation-algebra/x2f8bb11595b61c86:combine-like-terms/e/manipulating-linear-expressions-with-rational-coefficients 2023-12-11T22:13:00.981327266Z Combining like terms with rational coefficients Practice combining like terms for expressions that have rational coefficients. This requires adding and subtracting fractions. Justin Helps exercise https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:poly-arithmetic/x2ec2f6f830c9fb89:poly-add-sub/v/adding-and-subtracting-polynomials-1 2023-08-11T17:38:48.446343948Z Adding polynomials Learn how to simplify polynomials by combining like terms! Discover the power of adding and subtracting terms with the same degree of x. Uncover the magic of removing parentheses and grouping similar terms together to simplify complex expressions. Master the art of polynomial simplification! Sal Khan video https://cdn.kastatic.org/googleusercontent/P52_7TkuPy7FOhq7-OePwtVYkcBA9-pAdD1w7Uvek40918VCfTIlt6TgXnQzEE4212lDDjIebIeAbdfvLzdkO0lq Adding polynomials Learn how to simplify polynomials by combining like terms! Discover the power of adding and subtracting terms with the same degree of x. Uncover the magic of removing parentheses and grouping similar terms together to simplify complex expressions. Master the art of polynomial simplification! https://cdn.kastatic.org/ka-youtube-converted/ahdKdxsTj8E.mp4/ahdKdxsTj8E.mp4 121 Algebraic manipulation https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:poly-arithmetic/x2ec2f6f830c9fb89:poly-add-sub/v/subtracting-polynomials 2023-08-11T17:38:48.446343948Z Subtracting polynomials Master the art of adding and subtracting polynomials! Learn how to distribute negative signs across terms, combine like terms, and simplify expressions. This skill is key to understanding algebra and making math easier. Sal Khan video https://cdn.kastatic.org/googleusercontent/PGR9Z2IOnfKh7MWus7JU-aNIEKgaRIVq3fXAoZAK1UYQVq8sSroW476cJgoMTZFxYm-113UG20-1qy96K_DMxks Subtracting polynomials Master the art of adding and subtracting polynomials! Learn how to distribute negative signs across terms, combine like terms, and simplify expressions. This skill is key to understanding algebra and making math easier. https://cdn.kastatic.org/ka-youtube-converted/5ZdxnFspyP8.mp4/5ZdxnFspyP8.mp4 127 Algebraic manipulation https://www.khanacademy.org/math/algebra-1-eureka-squared-aligned/x15446f63b23e2a07:expressions-equations-and-inequalities-in-one-variable/x15446f63b23e2a07:adding-and-subtracting-polynomial-expressions/v/adding-and-subtracting-polynomials-of-degree-two 2024-06-10T22:09:52.259723494Z Adding and subtracting polynomials of degree two When given two polynomials of degree two, add or subtract to simplify. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/a54eacf6-8a1e-4581-ab48-c1f9da0e5708_1280_720_base.png Adding and subtracting polynomials of degree two When given two polynomials of degree two, add or subtract to simplify. https://cdn.kastatic.org/ka-youtube-converted/kieyGh0SDQk.mp4/kieyGh0SDQk.mp4 190 Algebraic manipulation https://www.khanacademy.org/math/grade-6-math-cambridge/x1977d7ef0ed7ac14:algebra/x1977d7ef0ed7ac14:polynomials/e/add-and-subtract-polynomials-of-degree-one 2026-02-04T18:23:39.297271444Z Add and subtract polynomials of degree one Given two polynomials and an instruction to add or subtract, find the solution. Nick Kokkinis exercise https://www.khanacademy.org/math/algebra-1-eureka-squared-aligned/x15446f63b23e2a07:expressions-equations-and-inequalities-in-one-variable/x15446f63b23e2a07:adding-and-subtracting-polynomial-expressions/e/add-and-subtract-polynomials-of-degree-2 2026-02-04T23:27:14.762735715Z Add and subtract polynomials of degree two When given two polynomials of degree two, add or subtract to simplify. Esther Mobille exercise https://www.khanacademy.org/math/algebra-home/alg-polynomials/alg-add-subtract-poly-two-var/e/adding-and-subtracting-polynomials-2 2025-02-27T11:46:16.621461116Z Add & subtract polynomials: two variables (intro) Example: Subtract (x²+2xy-y) and (3x+5xy+2y²). Tomer Gal exercise https://www.khanacademy.org/math/algebra2/x2ec2f6f830c9fb89:poly-arithmetic/x2ec2f6f830c9fb89:poly-add-sub/e/add---subtract-polynomials-challenge 2025-02-27T11:46:16.621461116Z Add & subtract polynomials Example: Subtract -2x²+4x-1 from 6x²+3x-9. Tomer Gal exercise