Question

What is the equation of the line in the following graph? 1)y=x+2

Answer 1

The slope-intercept form:

$y=mx+b$

m - slope

b - y-intercept

The formula of a slope:

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

We have two points (2, 0) and (-2, -4). Substitute:

$m=\dfrac{-4-0}{-2-2}=\dfrac{-4}{-4}=1$

Therefore we have the equation of a line

$y=1x+b\to y=x+b$

Put the coordinates of the point (2, 0) to the equation:

$0=2+b$     subtract 2 from both sides

$-2=b\to b=-2$

Answer: $\boxed{y=x-2}\to\boxed{3)}$