-300=t(10-4.9t)

Solution for -300=t(10-4.9t) equation:

-300=t(10-4.9t)

We move all terms to the left:

-300-(t(10-4.9t))=0

We add all the numbers together, and all the variables

-(t(-4.9t+10))-300=0


We calculate terms in parentheses: -(t(-4.9t+10)), so:

t(-4.9t+10)

We multiply parentheses

-4t^2+10t

Back to the equation:

-(-4t^2+10t)


We get rid of parentheses

4t^2-10t-300=0

a = 4; b = -10; c = -300;
Δ = b2-4ac
Δ = -102-4·4·(-300)
Δ = 4900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4900}=70$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-70}{2*4}=\frac{-60}{8}
=-7+1/2
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+70}{2*4}=\frac{80}{8}
=10
$