Y=-4.9x2+12.25x

Solution for Y=-4.9x2+12.25x equation:

=-4.9Y^2+12.25Y

We move all terms to the left:

-(-4.9Y^2+12.25Y)=0

We get rid of parentheses

4.9Y^2-12.25Y=0

a = 4.9; b = -12.25; c = 0;
Δ = b2-4ac
Δ = -12.252-4·4.9·0
Δ = 150.0625
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{-(-12.25)-\sqrt{150.0625}}{2*4.9}=\frac{12.25-\sqrt{150.0625}}{9.8}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12.25)+\sqrt{150.0625}}{2*4.9}=\frac{12.25+\sqrt{150.0625}}{9.8}
$