SOLUTION: this is a fraction problem numorator is 4 denominator -2+sqrt7

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Question 117269: this is a fraction problem
numorator is 4
denominator -2+sqrt7
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%284%29%2F%28-2%2Bsqrt%287%29%29 Start with the given expression


%28%284%29%2F%28-2%2Bsqrt%287%29%29%29%28%28-2-sqrt%287%29%29%2F%28-2-sqrt%287%29%29%29 Multiply by the fraction by %28-2-sqrt%287%29%29%2F%28-2-sqrt%287%29%29. Note -2-sqrt%287%29 is the conjugate of -2%2Bsqrt%287%29.


%28%284%29%28-2-sqrt%287%29%29%29%2F%28%28-2%2Bsqrt%287%29%29%28-2-sqrt%287%29%29%29 Combine the fractions


Foil the denominator


%28%284%29%28-2-sqrt%287%29%29%29%2F%28-2%2A-2%2Bsqrt%287%29%2Asqrt%287%29%29 Cancel like terms


%28%284%29%28-2-sqrt%287%29%29%29%2F%284-7%29 Multiply




%28%284%29%28-2-sqrt%287%29%29%29%2F%28-3%29 Combine like terms



%28%284%29%28-2%29%2B%284%29%28-sqrt%287%29%29%29%2F%28-3%29 Distribute


%28-8-4sqrt%287%29%29%2F%28-3%29 Multiply