-t=9(t-10)t=

Solution for -t=9(t-10)t= equation:

-t=9(t-10)t=

We move all terms to the left:

-t-(9(t-10)t)=0

We add all the numbers together, and all the variables

-1t-(9(t-10)t)=0


We calculate terms in parentheses: -(9(t-10)t), so:

9(t-10)t

We multiply parentheses

9t^2-90t

Back to the equation:

-(9t^2-90t)


We get rid of parentheses

-9t^2-1t+90t=0

We add all the numbers together, and all the variables

-9t^2+89t=0

a = -9; b = 89; c = 0;
Δ = b2-4ac
Δ = 892-4·(-9)·0
Δ = 7921
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7921}=89$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(89)-89}{2*-9}=\frac{-178}{-18}
=9+8/9
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(89)+89}{2*-9}=\frac{0}{-18}
=0
$