0.4x^2-4x+8.4=

Simple and best practice solution for 0.4x^2-4x+8.4= 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 0.4x^2-4x+8.4= equation: 


Simplifying
0.4x2 + -4x + 8.4 = 0

Reorder the terms:
8.4 + -4x + 0.4x2 = 0

Solving
8.4 + -4x + 0.4x2 = 0

Solving for variable 'x'.

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

Divide each side by '0.4'.
21 + -10x + x2 = 0

Move the constant term to the right:

Add '-21' to each side of the equation.
21 + -10x + -21 + x2 = 0 + -21

Reorder the terms:
21 + -21 + -10x + x2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -10x + x2 = 0 + -21
-10x + x2 = 0 + -21

Combine like terms: 0 + -21 = -21
-10x + x2 = -21

The x term is -10x.  Take half its coefficient (-5).
Square it (25) and add it to both sides.

Add '25' to each side of the equation.
-10x + 25 + x2 = -21 + 25

Reorder the terms:
25 + -10x + x2 = -21 + 25

Combine like terms: -21 + 25 = 4
25 + -10x + x2 = 4

Factor a perfect square on the left side:
(x + -5)(x + -5) = 4

Calculate the square root of the right side: 2

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


Subproblem 1
x + -5 = 2

Simplifying
x + -5 = 2

Reorder the terms:
-5 + x = 2

Solving
-5 + x = 2

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '5' to each side of the equation.
-5 + 5 + x = 2 + 5

Combine like terms: -5 + 5 = 0
0 + x = 2 + 5
x = 2 + 5

Combine like terms: 2 + 5 = 7
x = 7

Simplifying
x = 7


Subproblem 2
x + -5 = -2

Simplifying
x + -5 = -2

Reorder the terms:
-5 + x = -2

Solving
-5 + x = -2

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '5' to each side of the equation.
-5 + 5 + x = -2 + 5

Combine like terms: -5 + 5 = 0
0 + x = -2 + 5
x = -2 + 5

Combine like terms: -2 + 5 = 3
x = 3

Simplifying
x = 3


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

See similar equations:

| 160=9.7x | | 5/x=4/3x | | 20.00+6.00x=20 | | f=50+n-40/4 | | 2(x+8)=3(x+4) | | 4x^2+20x=-16 | | (x+4)=(2x-5) | | 1539=17.7x | | 4(8+6x)=104 | | 1.2x+1.2-5.4=-10 | | 2n-12n-14=0 | | -3(-2+2x)=-30 | | -4(t-5)+7t=9t-1 | | 783=7x | | 4(2x-3)-9(x+2)=0 | | 3z-1=7z-2 | | 100+15x=25+20x | | 195=6.4x | | 4(x+3)/3=2x-5 | | -4d=14 | | 5x=249.6 | | 4+2(x+3)=24 | | 4n+1.6=N | | 8x-3=3x+12 | | ((3)(2.5))-3(-2.5)+(-6)=x | | 4x+x^2=32 | | /2+4.82=2.57 | | -7=-11 | | 50000+100x= | | 2x+30=30+x | | 2(x+8)+2=18 | | 2n/5-3/7=27/35 |

Equations solver categories