Question

(7x²+2x+5)+(3x²-8x-10)

Answer 1

First you would simplify the equation (7x²+2x+5)+(3x²-8x-10) lets start with the first part 
(7x²+2x+5) 
7x² + 2x which = 49x + 2x which also = 51x Then you add the last part (+5) 
51x + 5
Now you simplify the last part.
(3x²-8x-10)
3x²-8x which=9x - 8x which also = 1x or simply x Then add the last part (-10) Which you'll get x-10 
51x + 5) + (x - 10) = 52x -5
so your answer is 52x - 5