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### Course: 8th grade>Unit 3

Lesson 13: Linear and nonlinear functions

# Linear & nonlinear functions: word problem

Learn to determine if the relationship described in a word problem is a function. Created by Sal Khan.

## Want to join the conversation?

• y=mx+b is a slope form. We use this to tell if it is a function or not. If it follows the formula y=mx+b then you know that it is proportional.
• is there a way to put memes on here because if i can im soo going to find captian kirk screaming KHAN! on here
(i just learned that his last name is khan)
• what would the linear equation be, if on a table the x value was 0, and the y value was 49, and the y value kept decreasing by -35 and the x value kept rising by 1.?
• I think that it would be: y=14x, and the y-intercept would be 0. The next two values in the table would be 14 and 1 because 49-35=14 and 0+1=1. Since 14 divided by 1 is still 14, the slope would be 14.
• is b the slope or initial value
• B is the y-intercept. that means where the line meets with the y-axis. you could also look at it like this. y=mx+b, if x equals 0 then m*0 is 0 then y would equal B. So B is the y-intercept(M is the slope).
• Say, (x) increases by 3 each time but what if (y) increased gradually. for example (x) goes, (1,3,6,9,12) and (y) went (4,5,7,10,14) would that be a linear or non-linear?
• It is definitely not linear, remember slope is (y2-y1)/(x2-x1) and this has to stay the same between any two points. The first two give (5-4)/(3-1)=1/2. The second and third give (7-5)/(6-3)=2/3 which are not the same.
• G
good video you should watch it's very helpful
• he mispronounced "bologna"