21n^2+8n-5=0

Simple and best practice solution for 21n^2+8n-5=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 21n^2+8n-5=0 equation:



21n^2+8n-5=0
a = 21; b = 8; c = -5;
Δ = b2-4ac
Δ = 82-4·21·(-5)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-22}{2*21}=\frac{-30}{42} =-5/7 $
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+22}{2*21}=\frac{14}{42} =1/3 $

See similar equations:

| 4^3x-1=16^5x | | k/6-8=1 | | 5p+2p+1=23 | | 3c=8.25 | | 6(-1/2)+2(n-3)=15 | | 5.50+12.50x=1400 | | -7(2-r)+13=55 | | 16s=23 | | 7x-3x0.75=-10 | | 7(x-3)+10=3 | | 12x–15=8x–10= | | a−9.2/3=7 | | 1/2x+7=1/4x+5 | | 5(4m+5)+3=128 | | 2=(1.035)^(2t) | | 6(-20.5+13)=4y–28 | | 96+(p+90)=(96+43)+90 | | 6(-2+n-3)=15 | | 5x2−7x+4=6x+105x2−7x+4=6x+10 | | 7x-3x0.75=10 | | 3y-2(y+3)=5 | | 10n=–8+9n | | -6(x+3)2=300 | | -4=q/16 | | 3/5g-1/3=-10/1 | | 0=7.6(-8u+10) | | -9+7a=61 | | -5x^2=2x-39 | | 8n+10=36 | | 8x-11=149 | | -18k=288 | | 3x-31=x+12 |

Equations solver categories