0=t(30.0-4.9t)

Solution for 0=t(30.0-4.9t) equation:

0=t(30.0-4.9t)

We move all terms to the left:

0-(t(30.0-4.9t))=0

We add all the numbers together, and all the variables

-(t(-4.9t+30))+0=0

We add all the numbers together, and all the variables

-(t(-4.9t+30))=0


We calculate terms in parentheses: -(t(-4.9t+30)), so:

t(-4.9t+30)

We multiply parentheses

-4t^2+30t

Back to the equation:

-(-4t^2+30t)


We get rid of parentheses

4t^2-30t=0

a = 4; b = -30; c = 0;
Δ = b2-4ac
Δ = -302-4·4·0
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-30}{2*4}=\frac{0}{8}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+30}{2*4}=\frac{60}{8}
=7+1/2
$