9r^2-9r-11=0

Simple and best practice solution for 9r^2-9r-11=0 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for 9r^2-9r-11=0 equation:



9r^2-9r-11=0
a = 9; b = -9; c = -11;
Δ = b2-4ac
Δ = -92-4·9·(-11)
Δ = 477
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:
$\sqrt{\Delta}=\sqrt{477}=\sqrt{9*53}=\sqrt{9}*\sqrt{53}=3\sqrt{53}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-3\sqrt{53}}{2*9}=\frac{9-3\sqrt{53}}{18} $
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+3\sqrt{53}}{2*9}=\frac{9+3\sqrt{53}}{18} $

See similar equations:

| p+12=54 | | 8a-1=1 | | 46=-6y | | 5v^2-18v+13=4 | | (x+93)(x+55)=180 | | 2s-16=-20 | | 5k^2+10=135 | | 20x200= | | -5+1=-5(x+3) | | 2a=391 | | 3-7r^2=-39 | | 8=6+b/2 | | y=25(1.2)^5. | | $y=25(1.2)^5. | | 6.3-12x=4.2x | | 15-0.45p=55-0.55p | | 15+0.45p=55+0.55p | | 9x=702 | | 6(3r-3)=108 | | 64^-5=2^x | | 0.79p+32=1.19p | | 4.2x=58 | | 6+3(6n-7)=-159 | | 6+3(6n+7)=-159 | | 6=3(6n-7)=-98 | | 7(7-3x)=-98 | | 4x(2x-3)=13 | | $y=350(1+0.75)^5 | | 1,695+x=2,475 | | -2x+7(-3)=15 | | -118=-10-6b | | h/26=-8 |

Equations solver categories