f^2+18f=47

Simple and best practice solution for f^2+18f=47 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 f^2+18f=47 equation:


Simplifying
f2 + 18f = 47

Reorder the terms:
18f + f2 = 47

Solving
18f + f2 = 47

Solving for variable 'f'.

Reorder the terms:
-47 + 18f + f2 = 47 + -47

Combine like terms: 47 + -47 = 0
-47 + 18f + f2 = 0

Begin completing the square.

Move the constant term to the right:

Add '47' to each side of the equation.
-47 + 18f + 47 + f2 = 0 + 47

Reorder the terms:
-47 + 47 + 18f + f2 = 0 + 47

Combine like terms: -47 + 47 = 0
0 + 18f + f2 = 0 + 47
18f + f2 = 0 + 47

Combine like terms: 0 + 47 = 47
18f + f2 = 47

The f term is 18f.  Take half its coefficient (9).
Square it (81) and add it to both sides.

Add '81' to each side of the equation.
18f + 81 + f2 = 47 + 81

Reorder the terms:
81 + 18f + f2 = 47 + 81

Combine like terms: 47 + 81 = 128
81 + 18f + f2 = 128

Factor a perfect square on the left side:
(f + 9)(f + 9) = 128

Calculate the square root of the right side: 11.313708499

Break this problem into two subproblems by setting 
(f + 9) equal to 11.313708499 and -11.313708499.

Subproblem 1

f + 9 = 11.313708499 Simplifying f + 9 = 11.313708499 Reorder the terms: 9 + f = 11.313708499 Solving 9 + f = 11.313708499 Solving for variable 'f'. Move all terms containing f to the left, all other terms to the right. Add '-9' to each side of the equation. 9 + -9 + f = 11.313708499 + -9 Combine like terms: 9 + -9 = 0 0 + f = 11.313708499 + -9 f = 11.313708499 + -9 Combine like terms: 11.313708499 + -9 = 2.313708499 f = 2.313708499 Simplifying f = 2.313708499

Subproblem 2

f + 9 = -11.313708499 Simplifying f + 9 = -11.313708499 Reorder the terms: 9 + f = -11.313708499 Solving 9 + f = -11.313708499 Solving for variable 'f'. Move all terms containing f to the left, all other terms to the right. Add '-9' to each side of the equation. 9 + -9 + f = -11.313708499 + -9 Combine like terms: 9 + -9 = 0 0 + f = -11.313708499 + -9 f = -11.313708499 + -9 Combine like terms: -11.313708499 + -9 = -20.313708499 f = -20.313708499 Simplifying f = -20.313708499

Solution

The solution to the problem is based on the solutions from the subproblems. f = {2.313708499, -20.313708499}

See similar equations:

| c-34=20 | | 2(a-5)=4a-(2a-10) | | 3g+2(-8+5g)=1-g | | -18=4-x | | 3z^2+60z-21=0 | | 12-5x=112 | | -7y+6=41y-2 | | q^2-9q=0 | | 19x-5=1+17x | | t^2-20t+21=0 | | -6x+4+4x=3x+9 | | 6+4q=8+3q | | 12+11=5x-3 | | 8(a-5)=88 | | 7t^2+50t=0 | | g^2+44g=0 | | u^2-28u=0 | | 13x-7y=12 | | y^2+y-50=0 | | n^2-26n+48=0 | | 21y^2+26y+8=0 | | 125=.05s^2+1.1s | | 6=-0.5714285714x-6 | | k^2+13k=0 | | 0=8-6m | | g^2+38g=0 | | 2x^2+12x=26 | | 2y-3x+5=5y+3 | | f^2+8f-20=0 | | 41x^2+12x=0 | | ln(4x-7)=ln(x+11) | | x^2-22x+40=0 |

Equations solver categories