Question

y must equal something,So solve from Y",This is confusing..

Answer 1

The slope-intercept form of a line:

$y=mx+b$

m - slope

b - y-intercept → (0, b)

The formula of a slope:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

We have two points from the graph (-4, -1) and (0, 3) → b = 3.

Substitute:

$m=\dfrac{3-(-1)}{0-(-4)}=\dfrac{4}{4}=1$

Answer: y = 1x + 3 → y = x + 3