Answer:
5x^2 +28x - 100
Explanation:
f(x)=7x^2−2 and g(x)=2(x−7)^2
First simplify g(x)
g(x) = 2 ( x-7)(x-7) = 2( x^2 - 7x -7x +49) = 2(x^2 -14x +49) = 2x^2 -28x +98
Now f(x) - g(x)
f(x) - g(x) = 7x^2−2 - (2x^2 -28x +98)
Distribute the minus sign
= 7x^2−2 - 2x^2 +28x -98
Combine like terms
= 5x^2 +28x - 100