-2r2+r+7=0

Simple and best practice solution for -2r2+r+7=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 -2r2+r+7=0 equation: 



-2r^2+r+7=0

a = -2; b = 1; c = +7;
Δ = b2-4ac
Δ = 12-4·(-2)·7
Δ = 57
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{57}}{2*-2}=\frac{-1-\sqrt{57}}{-4}
$


$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{57}}{2*-2}=\frac{-1+\sqrt{57}}{-4}
$

See similar equations:

| –x+8=11. | | Y=3x+15=9 | | 11.30.6x=8.3 | | 10y-50=5y+150 | | 26x=462 | | -34=j+-48 | | 2n-16+10=-42 | | 6=v/10 | | -1/2x=-1/6 | | 5(d+13)=1-5(3d-1) | | 8+3m=-4+m | | 8=5v+3 | | –9+2t=–t | | 9k+36-7k=32-2k+16 | | 8=5v | | 2x2+4x=3 | | 12-2h=h=21 | | 2(a-4)=(2a+8) | | 2y+19-135=180 | | (72x4)+(57x4)=500 | | ?x+20+3x=8x+10 | | 31.25-0.03g=29.95g | | 8(x+5)=-5x+27 | | 16x+48=28x+48 | | 1=−4(x−1)+4 | | 3=2x^2+5 | | -5.5=-2.33+3.17k | | 9d+7=7d+3 | | 2w-1=9-3w | | 20000=15000*1,0275^y | | 10t-6t-3=17 | | Y=15000*1,0275^x |

Equations solver categories