What is the remainder when 3x2 + 6x - 4 is divided by x + 2

Question

3x to the 2 power plus 6x minus 4 is divided by x plus 2

Answer 1

x+2 = x-(-2)

 

Let f(x) = 3x²+6x-4

 

By the Remainder Theorem, the remainder when f(x) is divided by x-(-2) is f(-2).

 

f(-2) = 3(-2)² + 6(-2) - 4 = -4

 

Answer 2

One may also use synthetic division to answer this question, putting -2 in the 'notch'.