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Solve this system : y(y-36)=-66

User Giacomelli
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1 Answer

2 votes
First, distribute the y into the parentheses;

y(y-36)=-66\\y^(2)-36=-66
Set all equal to 0;

y^(2)-36y=-66\\y^(2)-36y+66=0
That can't be factored normally, so use the quadratic formula;

\frac{-b(+-)\sqrt{b^(2)-4ac}}{2a}\\\\ \frac{-(-36)(+-)\sqrt{(-36)^(2)-4(1)(66)}}{2*1}\\\\ (36(+-)√(1296-264)))/(2)\\\\ (18(+-)√(1034))/(1)\\\\ 18(+-)√(1034)
The square root of 1034 cannot be simplified, so the solution(s) are:

y = 18+√(1034)=50.155870...
and

y=18-√(1034) = -14.155870...
User Susanne Jarl
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