(3x-15)+(x^2+x)=90

Simple and best practice solution for (3x-15)+(x^2+x)=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 (3x-15)+(x^2+x)=90 equation:


Simplifying
(3x + -15) + (x2 + x) = 90

Reorder the terms:
(-15 + 3x) + (x2 + x) = 90

Remove parenthesis around (-15 + 3x)
-15 + 3x + (x2 + x) = 90

Reorder the terms:
-15 + 3x + (x + x2) = 90

Remove parenthesis around (x + x2)
-15 + 3x + x + x2 = 90

Combine like terms: 3x + x = 4x
-15 + 4x + x2 = 90

Solving
-15 + 4x + x2 = 90

Solving for variable 'x'.

Reorder the terms:
-15 + -90 + 4x + x2 = 90 + -90

Combine like terms: -15 + -90 = -105
-105 + 4x + x2 = 90 + -90

Combine like terms: 90 + -90 = 0
-105 + 4x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '105' to each side of the equation.
-105 + 4x + 105 + x2 = 0 + 105

Reorder the terms:
-105 + 105 + 4x + x2 = 0 + 105

Combine like terms: -105 + 105 = 0
0 + 4x + x2 = 0 + 105
4x + x2 = 0 + 105

Combine like terms: 0 + 105 = 105
4x + x2 = 105

The x term is 4x.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4x + 4 + x2 = 105 + 4

Reorder the terms:
4 + 4x + x2 = 105 + 4

Combine like terms: 105 + 4 = 109
4 + 4x + x2 = 109

Factor a perfect square on the left side:
(x + 2)(x + 2) = 109

Calculate the square root of the right side: 10.440306509

Break this problem into two subproblems by setting 
(x + 2) equal to 10.440306509 and -10.440306509.

Subproblem 1

x + 2 = 10.440306509 Simplifying x + 2 = 10.440306509 Reorder the terms: 2 + x = 10.440306509 Solving 2 + x = 10.440306509 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = 10.440306509 + -2 Combine like terms: 2 + -2 = 0 0 + x = 10.440306509 + -2 x = 10.440306509 + -2 Combine like terms: 10.440306509 + -2 = 8.440306509 x = 8.440306509 Simplifying x = 8.440306509

Subproblem 2

x + 2 = -10.440306509 Simplifying x + 2 = -10.440306509 Reorder the terms: 2 + x = -10.440306509 Solving 2 + x = -10.440306509 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = -10.440306509 + -2 Combine like terms: 2 + -2 = 0 0 + x = -10.440306509 + -2 x = -10.440306509 + -2 Combine like terms: -10.440306509 + -2 = -12.440306509 x = -12.440306509 Simplifying x = -12.440306509

Solution

The solution to the problem is based on the solutions from the subproblems. x = {8.440306509, -12.440306509}

See similar equations:

| 12-4(n-2)= | | 3/4c=-12 | | yx-2= | | 13-8(1/2x-1) | | .3(y+5)-.1y= | | 6/8=15/x | | 10-8x=4x^2 | | -.6(r+4)+2.5r= | | 17x=19.5x+28 | | 17x=19.5+28 | | x+x+y+y=108 | | 6/30=x/20 | | 6/30=x/25 | | 17x=191/2x+28 | | 4-9K=-4K+19 | | 9-2x^2=-9 | | 8/36=x/63 | | 6/27=x/63 | | 8/36=x/27 | | Y=4y+40 | | (5x^5+7x)-(-5x^5-4x+7)= | | 6/14=x/28 | | -14-8d=-8c-14 | | 6/14=x/21 | | 8(x)+2(x)-2=75 | | -8+x^2=1 | | 10b-2=7 | | (-4)(5)= | | 2x+2y=108 | | (245-x)2=y | | 0=-16t^2+24 | | 9(2x-2)=3(6x+3) |

Equations solver categories