0=-4.9x^2+15x+60

Solution for 0=-4.9x^2+15x+60 equation:

0=-4.9x^2+15x+60

We move all terms to the left:

0-(-4.9x^2+15x+60)=0

We add all the numbers together, and all the variables

-(-4.9x^2+15x+60)=0

We get rid of parentheses

4.9x^2-15x-60=0

a = 4.9; b = -15; c = -60;
Δ = b2-4ac
Δ = -152-4·4.9·(-60)
Δ = 1401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-\sqrt{1401}}{2*4.9}=\frac{15-\sqrt{1401}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+\sqrt{1401}}{2*4.9}=\frac{15+\sqrt{1401}}{9.8}
$