(3x+1)(4x-7)=85

Simple and best practice solution for (3x+1)(4x-7)=85 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+1)(4x-7)=85 equation:



(3x+1)(4x-7)=85
We move all terms to the left:
(3x+1)(4x-7)-(85)=0
We multiply parentheses ..
(+12x^2-21x+4x-7)-85=0
We get rid of parentheses
12x^2-21x+4x-7-85=0
We add all the numbers together, and all the variables
12x^2-17x-92=0
a = 12; b = -17; c = -92;
Δ = b2-4ac
Δ = -172-4·12·(-92)
Δ = 4705
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-17)-\sqrt{4705}}{2*12}=\frac{17-\sqrt{4705}}{24} $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-17)+\sqrt{4705}}{2*12}=\frac{17+\sqrt{4705}}{24} $

See similar equations:

| X^3-3x=37 | | -(v-4)+5v=5(v-1) | | 24=15p-6 | | -8+25=4x+85 | | -3.2x+9=2.6 | | 8p-20=5p-(6-5p) | | 7x-3x+8=4 | | (7x-4)+(19)=(10x+3)=52 | | 9-6w=5 | | -87x+-1=21 | | (4x+4)+(2x-16)=180 | | 5x-9=33-3x | | 2(u-5)=18 | | -y-6-11=7 | | 8-3h=-3h+1 | | 87=2x+3 | | 6x-5+5=180 | | 6=4x-3x-2;x= | | 16=7/3x-2 | | d+4(d+6)=6(d+2 | | 6b+39=-(3+b) | | 3(2+x)-5x=16 | | –9b+9=–10b | | -0.7+2.4k=6 | | |5x-1|-21=-5. | | -5f=2f-7f | | 4b=−4 | | 5x/9=11 | | 2(r+5)-3=3(r-8)+20 | | x=56+155=180 | | 30x-13-2(17-3x)=2(4,5-26)+21x-3) | | 3x+2=-7x+11 |

Equations solver categories