4x-7x(x-9)=42

Simple and best practice solution for 4x-7x(x-9)=42 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 4x-7x(x-9)=42 equation:


Simplifying
4x + -7x(x + -9) = 42

Reorder the terms:
4x + -7x(-9 + x) = 42
4x + (-9 * -7x + x * -7x) = 42
4x + (63x + -7x2) = 42

Combine like terms: 4x + 63x = 67x
67x + -7x2 = 42

Solving
67x + -7x2 = 42

Solving for variable 'x'.

Reorder the terms:
-42 + 67x + -7x2 = 42 + -42

Combine like terms: 42 + -42 = 0
-42 + 67x + -7x2 = 0

Begin completing the square.  Divide all terms by
-7 the coefficient of the squared term: 

Divide each side by '-7'.
6 + -9.571428571x + x2 = 0

Move the constant term to the right:

Add '-6' to each side of the equation.
6 + -9.571428571x + -6 + x2 = 0 + -6

Reorder the terms:
6 + -6 + -9.571428571x + x2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -9.571428571x + x2 = 0 + -6
-9.571428571x + x2 = 0 + -6

Combine like terms: 0 + -6 = -6
-9.571428571x + x2 = -6

The x term is -9.571428571x.  Take half its coefficient (-4.785714286).
Square it (22.90306123) and add it to both sides.

Add '22.90306123' to each side of the equation.
-9.571428571x + 22.90306123 + x2 = -6 + 22.90306123

Reorder the terms:
22.90306123 + -9.571428571x + x2 = -6 + 22.90306123

Combine like terms: -6 + 22.90306123 = 16.90306123
22.90306123 + -9.571428571x + x2 = 16.90306123

Factor a perfect square on the left side:
(x + -4.785714286)(x + -4.785714286) = 16.90306123

Calculate the square root of the right side: 4.111333267

Break this problem into two subproblems by setting 
(x + -4.785714286) equal to 4.111333267 and -4.111333267.

Subproblem 1

x + -4.785714286 = 4.111333267 Simplifying x + -4.785714286 = 4.111333267 Reorder the terms: -4.785714286 + x = 4.111333267 Solving -4.785714286 + x = 4.111333267 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '4.785714286' to each side of the equation. -4.785714286 + 4.785714286 + x = 4.111333267 + 4.785714286 Combine like terms: -4.785714286 + 4.785714286 = 0.000000000 0.000000000 + x = 4.111333267 + 4.785714286 x = 4.111333267 + 4.785714286 Combine like terms: 4.111333267 + 4.785714286 = 8.897047553 x = 8.897047553 Simplifying x = 8.897047553

Subproblem 2

x + -4.785714286 = -4.111333267 Simplifying x + -4.785714286 = -4.111333267 Reorder the terms: -4.785714286 + x = -4.111333267 Solving -4.785714286 + x = -4.111333267 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '4.785714286' to each side of the equation. -4.785714286 + 4.785714286 + x = -4.111333267 + 4.785714286 Combine like terms: -4.785714286 + 4.785714286 = 0.000000000 0.000000000 + x = -4.111333267 + 4.785714286 x = -4.111333267 + 4.785714286 Combine like terms: -4.111333267 + 4.785714286 = 0.674381019 x = 0.674381019 Simplifying x = 0.674381019

Solution

The solution to the problem is based on the solutions from the subproblems. x = {8.897047553, 0.674381019}

See similar equations:

| 1.3x+4.19=1+2.4x | | 15x+10=13x+14 | | f(a+2)=a^2-6a+7 | | 70=10(2x-1) | | f(a+2)=x^2-6x+7 | | 10/x=15/2x-4 | | 9-9x=-144 | | 30x^5/10x^7 | | -8x+7y-28=0 | | 4x^2+56x-272=0 | | (4h^5k^3)(15k^2h^3)= | | 4-2+6x-1=17 | | 40x-10(10-x)=150 | | 21x=3x-12 | | X(50/3X) | | 30z^5/10z^7 | | (x+5)(x+3)=60 | | [13x-7-10x]=2 | | 4(2x+ay)= | | (y^2+8y+15)m^2=m(y+5) | | X+.02x=10.20 | | (y^2+8y+15)m^2=x(y+5) | | ln(x-5)-8=7 | | tanx(cotx-cosx)= | | 84=(-20x+4) | | f(x+2)=X^2+7x+5 | | 34(4x+4)=56+4(3m-4) | | 0x+0y-4=0 | | 4x^2+3x=360 | | 6y+90-9y=180 | | 800=20x+80y | | 25x-10=20x+25 |

Equations solver categories