I dont understand this question

.(3r²+7r+1)+(4r²-8r-2)

3 answers

This is not a question, it is an expression that can be simplified by combining like terms:

(3r²+7r+1)+(4r²-8r-2)

= 3r² + 4r² + 7r - 8r + 1 - 2

= 7r² - r - 1

Therefore, the simplified expression is 7r² - r - 1.
but why isnt 7r-8r=-1r?
You can also subtract the coefficients of r, which are 7 and (-8), to get:

7r - 8r = -1r

However, it's more common to combine the coefficients of the like terms without using negative coefficients, so you would write:

7r - 8r = -1r as -r

So, when we simplify the given expression:

(3r²+7r+1)+(4r²-8r-2)

We can combine the like terms to get:

3r² + 4r² = 7r²

7r - 8r = -r

1 - 2 = -1

Therefore, the simplified expression is:

7r² - r - 1