Question

find the missing value so that the line passing through the 2 points has the given slope:

Answer 1

The foruma for calculating the slope of a line passing through two points is expresses as;

$m\text{ = }\frac{y_2-y_1}{x_2-x_1}$

Given the coordinates (-20, y) and (-11, 15) with slope m = 0

Substitute the given parameters into the formula above and find y;

$\begin{gathered} 0\text{ = }\frac{15-y}{-11-(-20)} \\ 0\text{ = }\frac{15-y}{-11+20} \\ 0\text{ = }\frac{15-y}{9} \\ \text{cross multiply} \\ 0\text{ = 15-y} \\ y\text{ = 15} \end{gathered}$

Hence the value of y is 15. Option C is correct