Answer:
x is 7
Step-by-step explanation:
3x - 5(y + x)^2 = 16
3x - 16 = 5(y + x)^2
(y + x)^2 = 1/5(3x - 16) ------ eqn(I)
4x + 2(y + x)^2 = 30
2(y + x)^2 = 30 - 4x
(y + x)^2 = 1/2(30 - 4x) ------- eqn(II)
Equate eqn (I) & (II)
1/5(3x - 16) = 1/2(30 - 4x)
Multiply both sides by 10
2(3x - 16) = 5(30 - 4x)
6x - 32 = 150 - 20x
6x + 20x = 150 + 32
26x = 182
x = 182/26 = 7