Question

Simplify: 2x(x + 18) - x(4x - 2)
-2x2 + 38x
-2x2 + 38
-2x2 + 34

I did the work but I dont know what I did wrong can someone help me?

2x(x+18) - x(4x-2)
2x^2+36x - 4x -2x
2x2+36x- 2x
38x^2-2x

what did i do wrong?

Answer 1

2x(x+18) - x(4x-2)
You copied the problem correctly. That's the first step.

2x^2+36x - 4x -2x
Line above. Be careful distributing the -x in the second parentheses.
A negative outside the parentheses changes every sign inside the parentheses.
Also, remember, x(x) = x^2

The above line should read:
2x^2 + 36x - 4x^2 + 2x

Notice -4x^2, not -4x, and
notice the +2x, not -2x at the end.