T(9)=60p-p^2

Solution for T(9)=60p-p^2 equation:

(9)=60T-T^2

We move all terms to the left:

(9)-(60T-T^2)=0

We get rid of parentheses

T^2-60T+9=0

a = 1; b = -60; c = +9;
Δ = b2-4ac
Δ = -602-4·1·9
Δ = 3564
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$T_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$T_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3564}=\sqrt{324*11}=\sqrt{324}*\sqrt{11}=18\sqrt{11}$
$T_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-18\sqrt{11}}{2*1}=\frac{60-18\sqrt{11}}{2}
$
$T_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+18\sqrt{11}}{2*1}=\frac{60+18\sqrt{11}}{2}
$