Question

Draw a line with a slope of -1/2 going through the point (4,5) already graphed for you. At what point does this line cross the y-axis?

Answer 1

Answer: 7

Equation: y= -1/2x + 7

Explanation:

A slope of -1/2 means every x-value you go up by, the y-value goes down by 1/2.

To find an y-intercept you have to go back 4 x-values. So then you need to go up four 1/2 y-values. (simply 2 y-values).

Answer 2

Answer: What is the slope of this line? It's the 'm' term in y=mx+b. In this example, m=1. Therefore the slope of the line is 1, or said another way, the line goes "up" one unit every time it goes "over" one unit.

What is the y-intercept of the line? That's the 'b' term, so it's also 1. That means that when x is 0, y=1. Go ahead and plug x=0 into that equation to verify for yourself.

Explanation: