2x^2+7x+8=15

Simple and best practice solution for 2x^2+7x+8=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 2x^2+7x+8=15 equation:


Simplifying
2x2 + 7x + 8 = 15

Reorder the terms:
8 + 7x + 2x2 = 15

Solving
8 + 7x + 2x2 = 15

Solving for variable 'x'.

Reorder the terms:
8 + -15 + 7x + 2x2 = 15 + -15

Combine like terms: 8 + -15 = -7
-7 + 7x + 2x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-7 + 7x + 2x2 = 0

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

Divide each side by '2'.
-3.5 + 3.5x + x2 = 0

Move the constant term to the right:

Add '3.5' to each side of the equation.
-3.5 + 3.5x + 3.5 + x2 = 0 + 3.5

Reorder the terms:
-3.5 + 3.5 + 3.5x + x2 = 0 + 3.5

Combine like terms: -3.5 + 3.5 = 0.0
0.0 + 3.5x + x2 = 0 + 3.5
3.5x + x2 = 0 + 3.5

Combine like terms: 0 + 3.5 = 3.5
3.5x + x2 = 3.5

The x term is 3.5x.  Take half its coefficient (1.75).
Square it (3.0625) and add it to both sides.

Add '3.0625' to each side of the equation.
3.5x + 3.0625 + x2 = 3.5 + 3.0625

Reorder the terms:
3.0625 + 3.5x + x2 = 3.5 + 3.0625

Combine like terms: 3.5 + 3.0625 = 6.5625
3.0625 + 3.5x + x2 = 6.5625

Factor a perfect square on the left side:
(x + 1.75)(x + 1.75) = 6.5625

Calculate the square root of the right side: 2.561737691

Break this problem into two subproblems by setting 
(x + 1.75) equal to 2.561737691 and -2.561737691.

Subproblem 1

x + 1.75 = 2.561737691 Simplifying x + 1.75 = 2.561737691 Reorder the terms: 1.75 + x = 2.561737691 Solving 1.75 + x = 2.561737691 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.75' to each side of the equation. 1.75 + -1.75 + x = 2.561737691 + -1.75 Combine like terms: 1.75 + -1.75 = 0.00 0.00 + x = 2.561737691 + -1.75 x = 2.561737691 + -1.75 Combine like terms: 2.561737691 + -1.75 = 0.811737691 x = 0.811737691 Simplifying x = 0.811737691

Subproblem 2

x + 1.75 = -2.561737691 Simplifying x + 1.75 = -2.561737691 Reorder the terms: 1.75 + x = -2.561737691 Solving 1.75 + x = -2.561737691 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.75' to each side of the equation. 1.75 + -1.75 + x = -2.561737691 + -1.75 Combine like terms: 1.75 + -1.75 = 0.00 0.00 + x = -2.561737691 + -1.75 x = -2.561737691 + -1.75 Combine like terms: -2.561737691 + -1.75 = -4.311737691 x = -4.311737691 Simplifying x = -4.311737691

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.811737691, -4.311737691}

See similar equations:

| p=2k+2w | | 2(xx)+7x+8=15 | | -(-5-3v)=0 | | 11=3t+5 | | x^2+11=9x+3 | | -17x=-13 | | 5x-3x+3=12 | | g(x)=2x^2-3x+1 | | e-x=6 | | x^2+4x-24=8 | | 4+3y=43 | | x^2+20x+53= | | 4x+11=180 | | X^2-5=73 | | x+(x+9)=167 | | 12x^2-60=0 | | 5=-13-x | | x+9=-7 | | 8x=1500 | | (2-x)(3+x)=2(3-2x)(2-x) | | 5y+7=9+7y | | 18x=1500 | | 250x=1500 | | 583-3h=1667 | | 7x-9-x+3=0 | | 6x-7+9=3x | | 3+2(x-1)=-1 | | -3.8x=10.83 | | 10-4x=6x-5 | | 7x+x+100=1700 | | -2x+16=3x-44 | | -2x-26=62 |

Equations solver categories