20=-.2(x*x)+7.2x+1.5

Simple and best practice solution for 20=-.2(x*x)+7.2x+1.5 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 20=-.2(x*x)+7.2x+1.5 equation:


Simplifying
20 = -0.2(x * x) + 7.2x + 1.5

Multiply x * x
20 = -0.2(x2) + 7.2x + 1.5

Reorder the terms:
20 = 1.5 + 7.2x + -0.2x2

Solving
20 = 1.5 + 7.2x + -0.2x2

Solving for variable 'x'.

Combine like terms: 20 + -1.5 = 18.5
18.5 + -7.2x + 0.2x2 = 1.5 + 7.2x + -0.2x2 + -1.5 + -7.2x + 0.2x2

Reorder the terms:
18.5 + -7.2x + 0.2x2 = 1.5 + -1.5 + 7.2x + -7.2x + -0.2x2 + 0.2x2

Combine like terms: 1.5 + -1.5 = 0.0
18.5 + -7.2x + 0.2x2 = 0.0 + 7.2x + -7.2x + -0.2x2 + 0.2x2
18.5 + -7.2x + 0.2x2 = 7.2x + -7.2x + -0.2x2 + 0.2x2

Combine like terms: 7.2x + -7.2x = 0.0
18.5 + -7.2x + 0.2x2 = 0.0 + -0.2x2 + 0.2x2
18.5 + -7.2x + 0.2x2 = -0.2x2 + 0.2x2

Combine like terms: -0.2x2 + 0.2x2 = 0.0
18.5 + -7.2x + 0.2x2 = 0.0

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

Divide each side by '0.2'.
92.5 + -36x + x2 = 0

Move the constant term to the right:

Add '-92.5' to each side of the equation.
92.5 + -36x + -92.5 + x2 = 0 + -92.5

Reorder the terms:
92.5 + -92.5 + -36x + x2 = 0 + -92.5

Combine like terms: 92.5 + -92.5 = 0.0
0.0 + -36x + x2 = 0 + -92.5
-36x + x2 = 0 + -92.5

Combine like terms: 0 + -92.5 = -92.5
-36x + x2 = -92.5

The x term is -36x.  Take half its coefficient (-18).
Square it (324) and add it to both sides.

Add '324' to each side of the equation.
-36x + 324 + x2 = -92.5 + 324

Reorder the terms:
324 + -36x + x2 = -92.5 + 324

Combine like terms: -92.5 + 324 = 231.5
324 + -36x + x2 = 231.5

Factor a perfect square on the left side:
(x + -18)(x + -18) = 231.5

Calculate the square root of the right side: 15.215124055

Break this problem into two subproblems by setting 
(x + -18) equal to 15.215124055 and -15.215124055.

Subproblem 1

x + -18 = 15.215124055 Simplifying x + -18 = 15.215124055 Reorder the terms: -18 + x = 15.215124055 Solving -18 + x = 15.215124055 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '18' to each side of the equation. -18 + 18 + x = 15.215124055 + 18 Combine like terms: -18 + 18 = 0 0 + x = 15.215124055 + 18 x = 15.215124055 + 18 Combine like terms: 15.215124055 + 18 = 33.215124055 x = 33.215124055 Simplifying x = 33.215124055

Subproblem 2

x + -18 = -15.215124055 Simplifying x + -18 = -15.215124055 Reorder the terms: -18 + x = -15.215124055 Solving -18 + x = -15.215124055 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '18' to each side of the equation. -18 + 18 + x = -15.215124055 + 18 Combine like terms: -18 + 18 = 0 0 + x = -15.215124055 + 18 x = -15.215124055 + 18 Combine like terms: -15.215124055 + 18 = 2.784875945 x = 2.784875945 Simplifying x = 2.784875945

Solution

The solution to the problem is based on the solutions from the subproblems. x = {33.215124055, 2.784875945}

See similar equations:

| 7y/ | | 3m^2-m-4=0 | | (8x^5)^2/x^12 | | ((x^2-9)/4)/((3-x)/8)=10 | | 14+a=23 | | 1.4x-2.1=0.7x-0.06 | | 25/-2t | | 15x^2-3x-14=0 | | 9x-4=3x+16+x | | 7x-18+4x-2=180 | | -2x^2=16x+28 | | 3(4x+3)+2=5x-3 | | 15x^2-26x-3=5+8x^2 | | 1.4+0.05-0.8= | | 8y-28=y-7 | | 15x^2+2x+3=3+8x^2 | | 3(x+6)+8x=11x-18 | | 4x^2+4x=-10x-12 | | 3x^2-12x-2=-7 | | 6n^2+11n-28=7 | | -6x+9=-39 | | 38/3= | | 4(5n+6)=124 | | 2r+6=0 | | x^2+7x+6=x^2-8x | | 64r^2-328r+36=-4 | | (3y-12)/2 | | 9p^2-24p+16=0 | | 32=47 | | 16c+12=0 | | -40n+56=0 | | y=6X^2+6X |

Equations solver categories