4x^2+8x=9

Simple and best practice solution for 4x^2+8x=9 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 4x^2+8x=9 equation:


Simplifying
4x2 + 8x = 9

Reorder the terms:
8x + 4x2 = 9

Solving
8x + 4x2 = 9

Solving for variable 'x'.

Reorder the terms:
-9 + 8x + 4x2 = 9 + -9

Combine like terms: 9 + -9 = 0
-9 + 8x + 4x2 = 0

Begin completing the square.  Divide all terms by
4 the coefficient of the squared term: 

Divide each side by '4'.
-2.25 + 2x + x2 = 0

Move the constant term to the right:

Add '2.25' to each side of the equation.
-2.25 + 2x + 2.25 + x2 = 0 + 2.25

Reorder the terms:
-2.25 + 2.25 + 2x + x2 = 0 + 2.25

Combine like terms: -2.25 + 2.25 = 0.00
0.00 + 2x + x2 = 0 + 2.25
2x + x2 = 0 + 2.25

Combine like terms: 0 + 2.25 = 2.25
2x + x2 = 2.25

The x term is 2x.  Take half its coefficient (1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
2x + 1 + x2 = 2.25 + 1

Reorder the terms:
1 + 2x + x2 = 2.25 + 1

Combine like terms: 2.25 + 1 = 3.25
1 + 2x + x2 = 3.25

Factor a perfect square on the left side:
(x + 1)(x + 1) = 3.25

Calculate the square root of the right side: 1.802775638

Break this problem into two subproblems by setting 
(x + 1) equal to 1.802775638 and -1.802775638.

Subproblem 1

x + 1 = 1.802775638 Simplifying x + 1 = 1.802775638 Reorder the terms: 1 + x = 1.802775638 Solving 1 + x = 1.802775638 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1' to each side of the equation. 1 + -1 + x = 1.802775638 + -1 Combine like terms: 1 + -1 = 0 0 + x = 1.802775638 + -1 x = 1.802775638 + -1 Combine like terms: 1.802775638 + -1 = 0.802775638 x = 0.802775638 Simplifying x = 0.802775638

Subproblem 2

x + 1 = -1.802775638 Simplifying x + 1 = -1.802775638 Reorder the terms: 1 + x = -1.802775638 Solving 1 + x = -1.802775638 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1' to each side of the equation. 1 + -1 + x = -1.802775638 + -1 Combine like terms: 1 + -1 = 0 0 + x = -1.802775638 + -1 x = -1.802775638 + -1 Combine like terms: -1.802775638 + -1 = -2.802775638 x = -2.802775638 Simplifying x = -2.802775638

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.802775638, -2.802775638}

See similar equations:

| -10c(x+5)+62=19-19 | | 2(-4)+3=10 | | 2m^2-15m+25=0 | | x+6-9x=30 | | 3(3c-1)-6=6c+3 | | 2(4)+3=10 | | 2(4)+18=10 | | 8x-1=9x+5 | | 5(x-3)-30=0 | | 23+4y-6=13y-11-2y | | y^2-12y+34=0 | | x+23+4x=-23-4x-26 | | 2(g+6)=-20 | | 2(-4)+18=10 | | 4x^3-20=12 | | 25-6x=5x+4x | | 1.4b=b+8 | | 0=4x^2-12x+58 | | 2(4)+(3)=10 | | 6x-5=7x-9 | | 5d+2d+4d+1d=6 | | 3(3y+2)=-3y-18 | | 2a+8a=-15 | | 15a^2=36+33a | | 4x^2-6+1= | | 15a^2=36a+30 | | 7x^2-20x=0 | | 67y=33(2y+2) | | 5s^2+29s+36=0 | | x+2(3-x)=-3(x+2)-4 | | x^2-2ix+3=0 | | 9x+3y+10=180 |

Equations solver categories