Question

I need some help on number 15 please...

Answer 1

To solve this problem, all you need to do is make a standard graphing equation. The first step is finding mode using two points from the table. We'll use (1, 70) and (2, 90).
$\frac{y_{1}- y_{2} }{ x_{1}- x_{2}} \\ \frac{70-90}{1-2} \\ \frac{-20}{-1} \\ 20$
From the work, we've found that the slope of this equation is 20.

Next, we need to finish writing the equation and plug in the coordinates to solve for the y-intercept.
$y=20x+b \\ 90=20(2)+b \\ 90=40+b \\ (90)-40=(40+b)-40 \\ b=90-40 \\ b=50$

Now we have all the information we need to write our equation, which is:
y = 20x+50

Hope this helps!