3x(5x+7)=-45+51

Simple and best practice solution for 3x(5x+7)=-45+51 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(5x+7)=-45+51 equation:



3x(5x+7)=-45+51
We move all terms to the left:
3x(5x+7)-(-45+51)=0
We add all the numbers together, and all the variables
3x(5x+7)-6=0
We multiply parentheses
15x^2+21x-6=0
a = 15; b = 21; c = -6;
Δ = b2-4ac
Δ = 212-4·15·(-6)
Δ = 801
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:
$\sqrt{\Delta}=\sqrt{801}=\sqrt{9*89}=\sqrt{9}*\sqrt{89}=3\sqrt{89}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-3\sqrt{89}}{2*15}=\frac{-21-3\sqrt{89}}{30} $
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+3\sqrt{89}}{2*15}=\frac{-21+3\sqrt{89}}{30} $

See similar equations:

| 8.3b-9.9=123.73 | | 2x+6=9x+1 | | x2−12x=8 | | -240=20m | | 2a-18=12-8a | | -2.5n+1.5=-9.5 | | 8(8k-2)+8k=8(1+6k) | | -16(-0.25)=x | | 9x+1=13x-5 | | 30t=2.5 | | 2x=8-5x | | +6(1-5v)=54 | | 1+5n-4=-18 | | 0.35x=70 | | s-10/2=3 | | -12.41=x=-0.06 | | x+x(.15)=500 | | 0=1+4b-1 | | 2(x-9)+8-7x=40 | | 9+1/2x=4-2(x-5) | | 5+8y=0 | | 9x-40°-7x-4°=180° | | 2y-14=-98 | | 3-(2x-8)=7x-7 | | 6b-(b+2)+(-b+3)=15b-10= | | 18-6a=-2(5a+1) | | 6+3x=5x+18 | | x+9=4x-39 | | .3y-2.5=-2y+4.4 | | -2=3p+5+2 | | 18k-9=16k-9 | | 5=8x=0 |

Equations solver categories