Question 266900
{{{(x^2 - 3x - 40)/(x + 5)}}}
What do I multiply {{{x + 5}}} by to get {{{x^2 - 3x - 40}}}?
My first try is {{{x}}}
{{{x*(x + 5) = x^2 + 5x}}}
subtract this from {{{x^2 - 3x - 40}}}, I get
{{{-8x - 40}}}
Now what do I add to {{{x}}} to finish the division?
I'll try {{{-8}}}
{{{-8*(x + 5) = -8x - 40}}}
I'll subtract this from {{{-8x - 40}}}
I get {{{0}}}, so the division is finished with no remainder
The answer is {{{x - 8}}}
To prove it:
{{{(x + 5)*(x - 8) = x^2 - 3x - 40}}}
OK