5t(t+15)-8=58

Solution for 5t(t+15)-8=58 equation:

5t(t+15)-8=58

We move all terms to the left:

5t(t+15)-8-(58)=0

We add all the numbers together, and all the variables

5t(t+15)-66=0

We multiply parentheses

5t^2+75t-66=0

a = 5; b = 75; c = -66;
Δ = b2-4ac
Δ = 752-4·5·(-66)
Δ = 6945
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(75)-\sqrt{6945}}{2*5}=\frac{-75-\sqrt{6945}}{10}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(75)+\sqrt{6945}}{2*5}=\frac{-75+\sqrt{6945}}{10}
$