Maths Equation Question (1 Viewer)

[Edward2593]

Was wondering if I could get some help with this simultaneous equation question:

x²+y²=117
2x²-3y²=54

thanks in advanced

 

[jet]

y² = 117-x^2
2x² - 3(117 - x²) = 54
2x² - 351 + 3x² = 54
5x² - 351 = 54
5x²=405
x²=81
x = 9 or -9

y² = 117 - 81
= 36
y = 6 or -6

So the solutions are:
x = 9, y =6
x = 9, y =-6
x = -9, y =6
x = -9, y =-6

 

[ohexploitable]

From (1):

x²=117-y²

subs. into (2) and solve

EDIT: beaten

 

[Edward2593]

Thankyou both for your quick response!