If f (x) = 15x 2 + 10x, find f (-1)

Anyone know the answer?

I'm assuming the given function is f (x) = 15x^2 + 10x.

If so, then,

f (x) = 15x^2 + 10x

f (x) = 15 * (x) ^2 + 10 * (x)

f (-1) = 15 * (-1) ^2 + 10 * (-1) ... note how x is replaced with - 1

f (-1) = 15 * (1) + 10 * (-1)

f (-1) = 15 - 10

f (-1) = 5

Therefore the answer is 5