I dont understand this question
.(3r²+7r+1)+(4r²-8r-2)
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
To understand the given question, you need to simplify the expression (3r² + 7r + 1) + (4r² - 8r - 2).
To do this, you add like terms: the terms with the same variables and exponents.
First, combine the terms with "r²":
3r² + 4r² = 7r²
Next, combine the terms with "r":
7r - 8r = -r
Finally, combine the constant terms:
1 - 2 = -1
Now, putting it all together, the simplified expression is:
7r² - r - 1.