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Solve

\(2x+y=20\\x^2+xy=47\)

 Jul 7, 2020
 #1
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From 1st equation  y = 20 - 2x     sub this into 2nd eqaution

 

x^2 + x (20-2x) =47

-x^2 +20x - 47 = 0              quadratic equation shows x =   10 +-sqrt 53

 

sub into one of the equations (the first is easiest ) to find y = -2sqrt53    when x = 10 + sqrt 53

                                                                                   and y = 2 sqrt53    when x = 10 - sqrt53

 Jul 7, 2020

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