Question

find the value of 2x^2-x-2 if x=-1

Answer 1

2(-1)²-(-1)-2
2(1)+1-2
2+1-2
3-2
1

Answer 2

f(x) = 2x^2-x-2
f(-1) = 2(-1)^2 - (-1) -2
        = 2+1-2
        = 1

Hope it helps