The sum means addition.
Add the like terms together.
4x^3+2x^2-4x+3
+ 7x^3-4x^2+7x+8
4x^3 + 7x^3 = 11x^3
2x^2 + -4x^2 = -2x^2
-4x +7x = 3x
3 +8 = 11
The answer is : 11x^3 - 2x^2 + 3x + 11
The descriminant is b^2-4ac so for 26 it would be -5^2 - 4 (1) (7). The quadratic formula is -B plus or minus the square root of b squared minus 4ac over 2a
the least common multiple is 1,020 :)
The answer is 29. If you put it in an equation, it looks like 90=(x*3)+3. If you -3 from each side, you get 87=x*3. Divide each side by 3, and you get x=29.