Question

Write an equation in slope-intercept form of the line that passes through (7, 2) and (2, 12)

Answer 1

Step-by-step explanation:

the general slope intercept form is

y = ax + b

a is the slope, b is the y-intercept (when x=0).

the slope is the ratio y/x indicating how much y changes, when x changes for a certain amount of units when going from one point to another.

going from (7, 2) to (2, 12) :

x changes by -5 (from 7 to 2), y changes by +10 (from 2 to 12).

so, the slope is 10/-5 = -2

therefore, we have already

y = -2x + b

we get b by using the coordinates of one of the points as x and y. e.g. (7, 2)

2 = -2×7 + b = -14 + b

16 = b

so, the full line equation is

y = -2x + 16