9y^2+7y^2-2=0

Solution for 9y^2+7y^2-2=0 equation:

9y^2+7y^2-2=0

We add all the numbers together, and all the variables

16y^2-2=0

a = 16; b = 0; c = -2;
Δ = b2-4ac
Δ = 02-4·16·(-2)
Δ = 128
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{128}=\sqrt{64*2}=\sqrt{64}*\sqrt{2}=8\sqrt{2}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-8\sqrt{2}}{2*16}=\frac{0-8\sqrt{2}}{32}
=-\frac{8\sqrt{2}}{32}
=-\frac{\sqrt{2}}{4}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+8\sqrt{2}}{2*16}=\frac{0+8\sqrt{2}}{32}
=\frac{8\sqrt{2}}{32}
=\frac{\sqrt{2}}{4}
$