y-10=-0.04y^2

Solution for y-10=-0.04y^2 equation:

y-10=-0.04y^2

We move all terms to the left:

y-10-(-0.04y^2)=0

We get rid of parentheses

0.04y^2+y-10=0

a = 0.04; b = 1; c = -10;
Δ = b2-4ac
Δ = 12-4·0.04·(-10)
Δ = 2.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{2.6}}{2*0.04}=\frac{-1-\sqrt{2.6}}{0.08}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{2.6}}{2*0.04}=\frac{-1+\sqrt{2.6}}{0.08}
$