Hello, Jacqueline,
The basic equation of a straight line written in standard form is y = mx + b, where m is the "slope" and b is the "y-intercept."
Slope, m, is defined as the rate of change of y as a function of x. When x increase by 1, how much does y increase. This is sometimes called the "Rise"/"Run." These two values can be found from the two points provided:
(-2,5) and (-4,-5)
Rise = -5 -5 = -10
Run = -4-(-2) = -2
So the Rise/Run = -10/-2 = 5 [y will increase by 5 if x increases by 1].
This leads to y = 5x + b
To find b, enter one of the two points. Let's use (-2, 5).
5 = (5)*(-2) + b
b = 15
The equation becomes y = 5x + 15
Bob
