(7-6x)(1+3x)=3+21x

Simple and best practice solution for (7-6x)(1+3x)=3+21x 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 (7-6x)(1+3x)=3+21x equation:



(7-6x)(1+3x)=3+21x
We move all terms to the left:
(7-6x)(1+3x)-(3+21x)=0
We add all the numbers together, and all the variables
(-6x+7)(3x+1)-(21x+3)=0
We get rid of parentheses
(-6x+7)(3x+1)-21x-3=0
We multiply parentheses ..
(-18x^2-6x+21x+7)-21x-3=0
We get rid of parentheses
-18x^2-6x+21x-21x+7-3=0
We add all the numbers together, and all the variables
-18x^2-6x+4=0
a = -18; b = -6; c = +4;
Δ = b2-4ac
Δ = -62-4·(-18)·4
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-18}{2*-18}=\frac{-12}{-36} =1/3 $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+18}{2*-18}=\frac{24}{-36} =-2/3 $

See similar equations:

| 4n^2-16n-12=n^2 | | 9x-7+7x+1=90 | | u-(-1)=-6 | | 8x-5-3x=60 | | 4.3y=34.31 | | c+4=-12 | | 6n+7n+12+13n-16=360 | | w+8+2w=38 | | X-x-5=30 | | 0.4x+0.3(10)=0.2(x+40) | | 4v-2v=-30 | | b+(-5)=30 | | x/0.6=8.6 | | x+6/16=9/8+x-9/3 | | t/7-0.5=2.5 | | 8=k/4-12 | | 10x+6x=4 | | j/5+3=-13 | | i/5+3=-13 | | 4(x-2)=5(x-3 | | 7(1-x)+2=19 | | 8y​=5 | | 3(4)^x+2=21 | | i/5+3=13 | | 14^(x-2)=9 | | -12x^2-8x+20=0 | | 34=14g-8 | | 10f-40=-10 | | 2x+18=3x+1/2x+1.5 | | 3=x+3-x5 | | -(d+9)+10=-(3+d) | | 16+(c=17)+(16=c)=17 |

Equations solver categories