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