Question

How do you simplify the expression `x^2-4x+4(x^2+2x-5)`?

Answer 1

`5x^2+4x-20`

Explanation:

You start by expanding the brackets in `4(x^2+ 2x -5)` to get `4x^2+8x-20`
So the full equation is `x^2 - 4x + 4x^2+8x-20`.
You now need to collect like terms.
`x^2+4x^2 = 5x^2`
`-4x + 8x = 4x`
and `-20` is left with no other like terms.
Now your equation is `5x^2+4x-20`