5x^2-90=10-4x^2

Solution for 5x^2-90=10-4x^2 equation:

5x^2-90=10-4x^2

We move all terms to the left:

5x^2-90-(10-4x^2)=0

We get rid of parentheses

5x^2+4x^2-10-90=0

We add all the numbers together, and all the variables

9x^2-100=0

a = 9; b = 0; c = -100;
Δ = b2-4ac
Δ = 02-4·9·(-100)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-60}{2*9}=\frac{-60}{18}
=-3+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+60}{2*9}=\frac{60}{18}
=3+1/3
$