Write an equation in slope- intercept form of each line

Given the graphed function below which of the following orders pairs are found on the inverse function

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?

Which point-slope form equation represents a line that passes through (3,-2) with a slope of -4/5