### Home > A2C > Chapter 1 > Lesson 1.1.2 > Problem1-17

1-17.

In each of the following equations, what is $y$ when $x=2$? When $x=0$? Where would the graph of each equation cross the $y$−axis?

1. $y=3x+15$

• Replace $x$ with $2$ or $0$ and calculate.

$y=6+15$

$y=0+15$

The equation is already in slope intercept form, take the $b$ value. ($y=mx+b$) ($y$-intercept is $(0,15)$)

1. $y=3−3x$

• Replace $x$ with $2$ or $0$ and calculate.

• $y=3−0$

• $y=3−6$

• The equation is already in slope-intercept form, take the $b$ value. ($y=mx+b$) ($y$-intercept is $(0,3)$)