SOLUTION: Solve the given nonlinear system by the addition method. 4x^2–2y^2= –2 x^2+4y^2=40 Please show me the steps. thank you so much!!

Algebra ->  Systems-of-equations -> SOLUTION: Solve the given nonlinear system by the addition method. 4x^2–2y^2= –2 x^2+4y^2=40 Please show me the steps. thank you so much!!      Log On


   

Question 748794: Solve the given nonlinear system by the addition method.
4x^2–2y^2= –2
x^2+4y^2=40
Please show me the steps. thank you so much!!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Solve the given nonlinear system by the addition method.
4x^2 – 2y^2= –2
x^2 + 4y^2 = 40
:
Multiply the 1st equation by 2, add to the 2nd equation
8x^2 – 4y^2= –4
x^2 + 4y^2 = 40
--------------------Addition eliminates y^2, find x^2
9x^2 = 36
divide both sides by 9
x^2 = 4
x = +/-sqrt%284%29
x = +2,
x = -2
:
Find y using the 2nd equation, we know x^2 = 4
4 + 4y^2 = 40
4y^2 = 40 - 4
4y^2 = 36
divide both sides by 4
y^2 = 9
y = +/-sqrt%289%29
y = +3
y = -3
:
Check our solutions in the 1st equation
4(4) - 2(9) = -2