x^2+3x=90

Simple and best practice solution for x^2+3x=90 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 x^2+3x=90 equation:


Simplifying
x2 + 3x = 90

Reorder the terms:
3x + x2 = 90

Solving
3x + x2 = 90

Solving for variable 'x'.

Reorder the terms:
-90 + 3x + x2 = 90 + -90

Combine like terms: 90 + -90 = 0
-90 + 3x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '90' to each side of the equation.
-90 + 3x + 90 + x2 = 0 + 90

Reorder the terms:
-90 + 90 + 3x + x2 = 0 + 90

Combine like terms: -90 + 90 = 0
0 + 3x + x2 = 0 + 90
3x + x2 = 0 + 90

Combine like terms: 0 + 90 = 90
3x + x2 = 90

The x term is 3x.  Take half its coefficient (1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
3x + 2.25 + x2 = 90 + 2.25

Reorder the terms:
2.25 + 3x + x2 = 90 + 2.25

Combine like terms: 90 + 2.25 = 92.25
2.25 + 3x + x2 = 92.25

Factor a perfect square on the left side:
(x + 1.5)(x + 1.5) = 92.25

Calculate the square root of the right side: 9.604686356

Break this problem into two subproblems by setting 
(x + 1.5) equal to 9.604686356 and -9.604686356.

Subproblem 1

x + 1.5 = 9.604686356 Simplifying x + 1.5 = 9.604686356 Reorder the terms: 1.5 + x = 9.604686356 Solving 1.5 + x = 9.604686356 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = 9.604686356 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = 9.604686356 + -1.5 x = 9.604686356 + -1.5 Combine like terms: 9.604686356 + -1.5 = 8.104686356 x = 8.104686356 Simplifying x = 8.104686356

Subproblem 2

x + 1.5 = -9.604686356 Simplifying x + 1.5 = -9.604686356 Reorder the terms: 1.5 + x = -9.604686356 Solving 1.5 + x = -9.604686356 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = -9.604686356 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = -9.604686356 + -1.5 x = -9.604686356 + -1.5 Combine like terms: -9.604686356 + -1.5 = -11.104686356 x = -11.104686356 Simplifying x = -11.104686356

Solution

The solution to the problem is based on the solutions from the subproblems. x = {8.104686356, -11.104686356}

See similar equations:

| 8y=9y-9 | | 3=4a-2b | | -3x+5x-9=2(x-5)-4 | | 3x-7(2x-13)=3(-2x+8) | | 49+(-28)= | | 10p+9-11-p=-2(2p+2)-3(2p-2) | | 3m+zr=r-8f | | n+-4+2n=14 | | 4-8b=2b+1 | | 9(x+6)+63=180 | | 7(n+7)-(4-7n)=13n | | 3-8b=2b-1 | | X-40=-39 | | 2-8b=2b-1 | | 2+8b=2b-1 | | 3+8b=2b+3 | | 7y+5=5y+6 | | 4.5+3c=7.2-6c | | -0.5=0.3x-x | | 19x-15+15x-7=180 | | -4(v+3)+2v+6=7v+8 | | 5+8b=2b+5 | | -X=190 | | 3x-8x-13=-5x+9-13 | | -9a+3a=-36 | | 5-3x=34 | | 3x+4x+6=13 | | 6(4x+9)=24x+54 | | (3x-2)(3x-2)(3)=(3x-2)(5)+2 | | 7u+6=-3u-4 | | a+2a-1=20 | | -6=a+a+5 |

Equations solver categories