3x(x-1)=15

Simple and best practice solution for 3x(x-1)=15 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 3x(x-1)=15 equation:



3x(x-1)=15
We move all terms to the left:
3x(x-1)-(15)=0
We multiply parentheses
3x^2-3x-15=0
a = 3; b = -3; c = -15;
Δ = b2-4ac
Δ = -32-4·3·(-15)
Δ = 189
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:
$\sqrt{\Delta}=\sqrt{189}=\sqrt{9*21}=\sqrt{9}*\sqrt{21}=3\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-3\sqrt{21}}{2*3}=\frac{3-3\sqrt{21}}{6} $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+3\sqrt{21}}{2*3}=\frac{3+3\sqrt{21}}{6} $

See similar equations:

| 9m–3–5m=3+4m–6 | | 4t=13-3 | | 55+3x=19 | | 4n-12=9-3n | | 1+4x=x+8 | | 55-3x=19 | | 8x+7=27+3x | | 7k-9=11+3k | | 2^2x+4-(5)2^x+1+1=40 | | x(5x-5)=1050 | | x+(x*0.75)=10 | | 15x=25+12.5x | | x+(x*0.75)=13 | | x+(x*0.75)=11 | | x+(x*0.75)=15 | | x+(x*0.75)=22 | | 5x2+11x=0 | | x+(x*0.75)=16 | | -23=1/5h+5 | | 2(x+5)=24+9x | | 1400=100x | | 2x+5=9x−44 | | (x+4)(x+8)=221 | | -3u+15u+7u=8u+43 | | 13-6x=6x=1 | | 5x2−26x=−5 | | 3(x-3)^3=375 | | 4÷x-4=8÷3x-19 | | (2x+10)(2x-10)=90 | | 2*x+x*√2=90 | | 4x^2-49x+16=0 | | 2p-1=2+ |

Equations solver categories