Expand and simplify (I've spent 5 hours trying to solve this

Expand and simplify:

6(m - 6) - 8(m-4)^2 + 4(m + 4)^2

I spent 5 HOURS today trying to get my answer to match the one in the book. The book says the answer to this is 2m^2 + 24m + 152.

I get the answer down to is: 6m -36 + 4m^2 + 32m + 64 -8m^2 + 64m - 128. When i substitute "m" for the number 5 in the original expression, and substitute "m" for the number 5 in my more simplified expression (6m -36 + 4m^2 + 32m + 64 -8m^2 + 64m - 128) the answers are the same. Which means i'm right doesnt it? But if i simplify my answer more by adding and subtracting the like terms it doesn't work anymore and it also doesn't match the answer in the book.

What the heck am i doing wrong?

BTW: ^2 means squared.

Re: Expand and simplify (I've spent 5 hours trying to solve

Someimes books are incorrect, and one finds this out after long deliberation trying to get ones answer to match.

It simplifies to \(\displaystyle -4m^{2}+102m-100=-2(2m^{2}-51m+50)\)

Re: Expand and simplify (I've spent 5 hours trying to solve

galactus said:

Someimes books are incorrect, and one finds this out after long deliberation trying to get ones answer to match.

It simplifies to \(\displaystyle -4m^{2}+102m-100=-2(2m^{2}-51m+50)\)

Click to expand...

Did you expand and simplify the original question to get that? Or did you just simplify my answer further?

So was i right after all?

Re: Expand and simplify (I've spent 5 hours trying to solve

I done it from the original problem. But yours is also correct. The book is incorrect.

Re: Expand and simplify (I've spent 5 hours trying to solve

einstein said:

6(m - 6) - 8(m-4)^2 + 4(m + 4)^2
I spent 5 HOURS today trying to get my answer to match the one in the book.
The book says the answer to this is 2m^2 + 24m + 152.

Click to expand...

The book's answer is correct IF the 1st term is 6(m - 6)^2 :shock:

If YOU're the one who copied it down wrong, then give yourself a fieldgoal kick!

Re: Expand and simplify (I've spent 5 hours trying to solve

Denis said:

einstein said:

6(m - 6) - 8(m-4)^2 + 4(m + 4)^2
I spent 5 HOURS today trying to get my answer to match the one in the book.
The book says the answer to this is 2m^2 + 24m + 152.

Click to expand...

The book's answer is correct IF the 1st term is 6(m - 6)^2 :shock:

If YOU're the one who copied it down wrong, then give yourself a fieldgoal kick!

Click to expand...

Yes, some people in another forum said that too. But i DID copy it correctly. There is NO squared in the book. The book has made a typo.

Lesson learned, don't always trust the book!

Re: Expand and simplify (I've spent 5 hours trying to solve

galactus said:

I done it from the original problem. But yours is also correct. The book is incorrect.

Click to expand...

Thanks for helping me!