0=(15-4.9t)t

Solution for 0=(15-4.9t)t equation:

0=(15-4.9t)t

We move all terms to the left:

0-((15-4.9t)t)=0

We add all the numbers together, and all the variables

-((-4.9t+15)t)+0=0

We add all the numbers together, and all the variables

-((-4.9t+15)t)=0


We calculate terms in parentheses: -((-4.9t+15)t), so:

(-4.9t+15)t

We multiply parentheses

-4t^2+15t

Back to the equation:

-(-4t^2+15t)


We get rid of parentheses

4t^2-15t=0

a = 4; b = -15; c = 0;
Δ = b2-4ac
Δ = -152-4·4·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-15}{2*4}=\frac{0}{8}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+15}{2*4}=\frac{30}{8}
=3+3/4
$