-0.5(x^2+4x-21)=0

Simple and best practice solution for -0.5(x^2+4x-21)=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 -0.5(x^2+4x-21)=0 equation:


Simplifying
-0.5(x2 + 4x + -21) = 0

Reorder the terms:
-0.5(-21 + 4x + x2) = 0
(-21 * -0.5 + 4x * -0.5 + x2 * -0.5) = 0
(10.5 + -2x + -0.5x2) = 0

Solving
10.5 + -2x + -0.5x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-0.5 the coefficient of the squared term: 

Divide each side by '-0.5'.
-21 + 4x + x2 = 0

Move the constant term to the right:

Add '21' to each side of the equation.
-21 + 4x + 21 + x2 = 0 + 21

Reorder the terms:
-21 + 21 + 4x + x2 = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 4x + x2 = 0 + 21
4x + x2 = 0 + 21

Combine like terms: 0 + 21 = 21
4x + x2 = 21

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 = 21 + 4

Reorder the terms:
4 + 4x + x2 = 21 + 4

Combine like terms: 21 + 4 = 25
4 + 4x + x2 = 25

Factor a perfect square on the left side:
(x + 2)(x + 2) = 25

Calculate the square root of the right side: 5

Break this problem into two subproblems by setting 
(x + 2) equal to 5 and -5.

Subproblem 1

x + 2 = 5 Simplifying x + 2 = 5 Reorder the terms: 2 + x = 5 Solving 2 + x = 5 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 = 5 + -2 Combine like terms: 2 + -2 = 0 0 + x = 5 + -2 x = 5 + -2 Combine like terms: 5 + -2 = 3 x = 3 Simplifying x = 3

Subproblem 2

x + 2 = -5 Simplifying x + 2 = -5 Reorder the terms: 2 + x = -5 Solving 2 + x = -5 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 = -5 + -2 Combine like terms: 2 + -2 = 0 0 + x = -5 + -2 x = -5 + -2 Combine like terms: -5 + -2 = -7 x = -7 Simplifying x = -7

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3, -7}

See similar equations:

| (3x-7y+7)dx-(3x-7y-3)dy=0 | | C=5/9*(179-32) | | 24j-54=186 | | (-10)-5x=25 | | -37+27x=11x+2 | | 1-(3x)=-1 | | 3-(3x)=9 | | 13-9w=-23 | | 8-(3x)=-1 | | log(5)(4x-1)=2 | | 35=3k | | (2cis45)/(10e^((2*3.14)/3(i))) | | sqrt(9-7x)=sqrt(3x+19) | | 18y-8=28-14y | | x=20x+3x^2 | | 18-5c=-2(6c+4) | | sqrt(3x^2+12x+13)=2x+5 | | y=lnx^5 | | 10(n-10)=-(4n+2) | | 2logx=(10-3x) | | -2(3x-1)-7=5(x+4)+8 | | z-5/6=7/6 | | -0.2(-x+6)+x=0.3(4-x) | | (4x-2)*3x=122 | | 8=-14m-34 | | 2x^3-18x^2-8x+72=0 | | 9=16-7x | | -5a+2b-7c+6c-3b+3a= | | 82-34/4 | | 3r^2-13rt+15r-65t= | | 6+48t-16t^2=0 | | 6=4-2(y) |

Equations solver categories