If f(x) varies directly with x and f(x) = 50 when x = -10, then what is f(x) when x = 15

Aline passes through (1,-5) and(-3,7) write an equation for the line in point slope form rewrite the equation in slope intercept form

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g

Which of the following circles have their centers in the third quadrant? check all that apply.