Question

Find the value of the expression:

–2x(x^2–x+3)+x(2x^2+x–5) for x=3; −3

Answer 1

you have –2x(x^2–x+3)+x(2x^2+x–5)
so, for x=3, that is
–2*3(3^2–3+3)+3(2*3^2+3–5)
= -6(9)+3(16)
= -54+48
= -6

or, since –2x(x^2–x+3)+x(2x^2+x–5) = 3x^2-11x, that would be
3*9-33 = 27-33 = -6

I'm sure you can do it now for x = -3, eh?

Answer 2

thanks