Remainder theorem?

Question

Use the remainder theorem to find the remainder when 1x^3 - 3x^2 - 9x + 50 is divided by 2x + 7. Round your answer to the nearest hundredth.

Answer 1

The remainder theorem is where you substitute one a number into an equation to find the remainder. Basically this means converting a linear factor (2x + 7) into a nuimber then putting it in place of x in the original equation. Then calculate the answer, this is the remainder. If the answer is 0, then the number is a factor and there is no remainder.
Convert into a linear factor:
2x + 7 = 0
2x = -7
x = -7/2
Replace x with -7/2
R = 1(-7/2)^3 - 3(-7/2)^2 - 9(-7/2) + 50
R = The remainder.
You can round it off yourself.

Answer 2

You have to use long division, like you learned way back in 3rd grade, and then keep track of the terms and numbers as they slew off and down to the right

2x+7]x^3-3x^2-9x+50
But it is impossible to show here properly as you have to put results above the line and I can't find the right key-combination..