Answer:
- 9x² + 10x + 4
Step-by-step explanation:
Calculate the subtraction as
- 4x² + 2x - 8 - (5x² - 8x - 12 ) ← distribute parenthesis by - 1
= - 4x² + 2x - 8 - 5x² + 8x + 12 ← collect like terms
= - 9x² + 10x + 4
Answer:

That is what the expression would be
It is asking you to find the sum of k^2 - 1 from k=1 to k=4. Since that is only 4 numbers, calculating the sum by hand wouldn’t be that bad.
(1^2 - 1) + (2^2 - 1) + (3^2 - 1) + (4^2 - 1) = 26
The easier way to find the sum is to use a few simple formulas.
When we have a term that is just a constant c, the formula is c*n.
When we have a variable k, the formula is k*n*(n+1)/2.
When we have a squared variable, the formula is k*n*(n+1)*(2n+1)/6.
In this case, we have a squared variable k^2 and a constant of -1.
So plug in n=4 to the formulas:
4*5*9/6 - 1*4 = 26
The answer is 26
Answer:
70 and 110
Step-by-step explanation:
First angle -- 2x
Second angle -- 3x + 5
Therefore,
2x + 3x + 5 = 180
5x = 175
x = 35
Therefore, 2x -- 70
3x + 5 -------------110
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