Slope-intercept form is y=mx+b, where m is the slope and b is the y-intercept.
The change from y=2x+7 to y=12x+7 is that 2 is changed to 12. Both 2 and 12 are in the place of m, meaning they are the slope.
This means the y-intercept stays the same; they start in the same position.
The slope, or rate of change, changes from 2 to 12. Since both are positive, the line will continue to point up (increase). However, an increase in slope means the line will increase more quickly, which results in a steeper line.
What you need to do is to find a multiple of 20 and 16 in other words a number that can multiply into 20 and 16. You have 2 and you have 4. So now this is how it looks like.
