Divide using synthetic division (2x^3 + 14x^2 - 58x) / (x + 10) 58

-10 | 2 14 -58
-20 -60
2 -6 -118

So it's 2x^2 -6x The remainer is -118

Set x + 10 = 0

So that's how I get -10

I then multiplied -10 x 2 to get -20 and placed it below 14. -20 + 14 is -6. -6 x -10 is -60. -58 + -60 is -118. 2 remains the same since you didn't do anything with.

Since you started with 2x^3 and this is division, you immediately know the first term will start with x^2 so that's how I get 2x^2. The ending number, in this case -118, is always the remainder.