Question

simplify
(7x^2-9)-(8+3x)-(2x^2-8x)

Answer 1

So again, start looking at common terms.

You have 7 x-squareds at the front, any other x-squareds?

Answer 2

3x

Answer 3

Those are xes, not x-squareds.

Answer 4

You have 3 different 'types' of terms here. You have terms of 'ones' (the ones with no x), terms of 'xes' (the ones with an x) and terms of 'x-squareds' (the ones with x^2)

Answer 5

So looking at your expression you have 7 x-squareds, and you subtract 2 x-squareds. Since there are no other x-squareds, how many will you have at the end?

Answer 6

5x

Answer 7

5x^2

Answer 8

Ok, so now that the hard part is done, look at the x terms. What do you see?

Answer 9

Try to set it up the way I was.

Answer 10

5x^2-11x-17

Answer 11

Nicely done. The only problem is the -11x in the middle.

Answer 12

Because you start with a -3x from the second set of parens. Then you subtract a -8x from the last set.

-3x - -8x =?

Answer 13

so then it would 5x^2+5-17

Answer 14

5x^2 + 5x - 17 is correct.

Answer 15

thanks