3x+x^2-84=0

Simple and best practice solution for 3x+x^2-84=0 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+x^2-84=0 equation:


Simplifying
3x + x2 + -84 = 0

Reorder the terms:
-84 + 3x + x2 = 0

Solving
-84 + 3x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '84' to each side of the equation.
-84 + 3x + 84 + x2 = 0 + 84

Reorder the terms:
-84 + 84 + 3x + x2 = 0 + 84

Combine like terms: -84 + 84 = 0
0 + 3x + x2 = 0 + 84
3x + x2 = 0 + 84

Combine like terms: 0 + 84 = 84
3x + x2 = 84

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 = 84 + 2.25

Reorder the terms:
2.25 + 3x + x2 = 84 + 2.25

Combine like terms: 84 + 2.25 = 86.25
2.25 + 3x + x2 = 86.25

Factor a perfect square on the left side:
(x + 1.5)(x + 1.5) = 86.25

Calculate the square root of the right side: 9.287087811

Break this problem into two subproblems by setting 
(x + 1.5) equal to 9.287087811 and -9.287087811.

Subproblem 1

x + 1.5 = 9.287087811 Simplifying x + 1.5 = 9.287087811 Reorder the terms: 1.5 + x = 9.287087811 Solving 1.5 + x = 9.287087811 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 = 9.287087811 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = 9.287087811 + -1.5 x = 9.287087811 + -1.5 Combine like terms: 9.287087811 + -1.5 = 7.787087811 x = 7.787087811 Simplifying x = 7.787087811

Subproblem 2

x + 1.5 = -9.287087811 Simplifying x + 1.5 = -9.287087811 Reorder the terms: 1.5 + x = -9.287087811 Solving 1.5 + x = -9.287087811 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 = -9.287087811 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = -9.287087811 + -1.5 x = -9.287087811 + -1.5 Combine like terms: -9.287087811 + -1.5 = -10.787087811 x = -10.787087811 Simplifying x = -10.787087811

Solution

The solution to the problem is based on the solutions from the subproblems. x = {7.787087811, -10.787087811}

See similar equations:

| 16=a-5.2 | | (3.14)(6.2)= | | X^2+18x-80=120 | | -33+z=-36 | | 4(2x-6)=3(2x-6) | | f(12)=-6*12 | | 8x-3x+9-7x+70=6x-50 | | 3a-10=4+q | | 3a+1=20 | | 20x-7-14x=3(2x-3)+2 | | -15.7+3.02= | | 5x-6+4x+7=180 | | 4n+5n=5n+7n | | 8x=y+2 | | 11+12=34 | | 30+3x=9x | | 48/3.68= | | 10+5x=3-2x | | 24=n*-4 | | 9x-(3x-12)=42 | | 7(2z-6)=5(x+6) | | u^2+6u+10=0 | | 8t^2+15t+39=0 | | 7x-4x+8=6x-4 | | 3x+9-9x=17-17x+11x-8 | | 18+4x=5+20x | | 3x+9-9x=17-17x+11 | | 49r^3+42r^2-42r-36= | | 2.5y=1.0 | | -4x+12=-8x-7 | | -2-(3-6p)= | | 10x+3=9+4x |

Equations solver categories