u^2-16u+21=0

Simple and best practice solution for u^2-16u+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 u^2-16u+21=0 equation:


Simplifying
u2 + -16u + 21 = 0

Reorder the terms:
21 + -16u + u2 = 0

Solving
21 + -16u + u2 = 0

Solving for variable 'u'.

Begin completing the square.

Move the constant term to the right:

Add '-21' to each side of the equation.
21 + -16u + -21 + u2 = 0 + -21

Reorder the terms:
21 + -21 + -16u + u2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -16u + u2 = 0 + -21
-16u + u2 = 0 + -21

Combine like terms: 0 + -21 = -21
-16u + u2 = -21

The u term is -16u.  Take half its coefficient (-8).
Square it (64) and add it to both sides.

Add '64' to each side of the equation.
-16u + 64 + u2 = -21 + 64

Reorder the terms:
64 + -16u + u2 = -21 + 64

Combine like terms: -21 + 64 = 43
64 + -16u + u2 = 43

Factor a perfect square on the left side:
(u + -8)(u + -8) = 43

Calculate the square root of the right side: 6.557438524

Break this problem into two subproblems by setting 
(u + -8) equal to 6.557438524 and -6.557438524.

Subproblem 1

u + -8 = 6.557438524 Simplifying u + -8 = 6.557438524 Reorder the terms: -8 + u = 6.557438524 Solving -8 + u = 6.557438524 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '8' to each side of the equation. -8 + 8 + u = 6.557438524 + 8 Combine like terms: -8 + 8 = 0 0 + u = 6.557438524 + 8 u = 6.557438524 + 8 Combine like terms: 6.557438524 + 8 = 14.557438524 u = 14.557438524 Simplifying u = 14.557438524

Subproblem 2

u + -8 = -6.557438524 Simplifying u + -8 = -6.557438524 Reorder the terms: -8 + u = -6.557438524 Solving -8 + u = -6.557438524 Solving for variable 'u'. Move all terms containing u to the left, all other terms to the right. Add '8' to each side of the equation. -8 + 8 + u = -6.557438524 + 8 Combine like terms: -8 + 8 = 0 0 + u = -6.557438524 + 8 u = -6.557438524 + 8 Combine like terms: -6.557438524 + 8 = 1.442561476 u = 1.442561476 Simplifying u = 1.442561476

Solution

The solution to the problem is based on the solutions from the subproblems. u = {14.557438524, 1.442561476}

See similar equations:

| 15+26d=-8d^22 | | X/2--17=23 | | -36-10y=14 | | 8(x-4)=104 | | 25/45,45,69/15 | | 36=-2x-15 | | 4x^2+7x+24=0 | | 3x+2(2x-2)=2(2x+2) | | 5y+14=3y+14 | | 3z-8z=84-99 | | 1x+12=2X+6 | | 54x=27x | | 3y=-23x-19 | | x/16-3 | | 23x+3y=-19 | | ht=128t^2-16t | | 448x^5-875x^2=0 | | 80+10x+2=24x-2 | | ht=128t-16t | | -x/6-3=-9 | | 1x=11 | | 0=-16t^2-600 | | 2.5=1x | | y-5=-9/8(x-3 | | 5=-5n | | 12x^2+x-13=0 | | 65+65+x+58=180 | | 3b+a=20 | | 0=x^3+15x^2+48x+32 | | 2x^2+16x+57=0 | | 9x=6+6y | | 12x-12=8+4 |

Equations solver categories