F(x)=2(5x+7) find f(-2)

Oh how fun, functions!! You substitute f(-2) into your starting function so it will look like this:
f(x)=2(5x+7)
f(x)=10x+14
f(-2)=10(-2)+14
f(-2)=(-20)+14
f(-2)=(-6)
divide by negative 2 on each side to find f:
f=3
Hope this helped!!