5x^2-25x-21=0

Simple and best practice solution for 5x^2-25x-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 5x^2-25x-21=0 equation:


Simplifying
5x2 + -25x + -21 = 0

Reorder the terms:
-21 + -25x + 5x2 = 0

Solving
-21 + -25x + 5x2 = 0

Solving for variable 'x'.

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

Divide each side by '5'.
-4.2 + -5x + x2 = 0

Move the constant term to the right:

Add '4.2' to each side of the equation.
-4.2 + -5x + 4.2 + x2 = 0 + 4.2

Reorder the terms:
-4.2 + 4.2 + -5x + x2 = 0 + 4.2

Combine like terms: -4.2 + 4.2 = 0.0
0.0 + -5x + x2 = 0 + 4.2
-5x + x2 = 0 + 4.2

Combine like terms: 0 + 4.2 = 4.2
-5x + x2 = 4.2

The x term is -5x.  Take half its coefficient (-2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
-5x + 6.25 + x2 = 4.2 + 6.25

Reorder the terms:
6.25 + -5x + x2 = 4.2 + 6.25

Combine like terms: 4.2 + 6.25 = 10.45
6.25 + -5x + x2 = 10.45

Factor a perfect square on the left side:
(x + -2.5)(x + -2.5) = 10.45

Calculate the square root of the right side: 3.232645975

Break this problem into two subproblems by setting 
(x + -2.5) equal to 3.232645975 and -3.232645975.

Subproblem 1

x + -2.5 = 3.232645975 Simplifying x + -2.5 = 3.232645975 Reorder the terms: -2.5 + x = 3.232645975 Solving -2.5 + x = 3.232645975 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2.5' to each side of the equation. -2.5 + 2.5 + x = 3.232645975 + 2.5 Combine like terms: -2.5 + 2.5 = 0.0 0.0 + x = 3.232645975 + 2.5 x = 3.232645975 + 2.5 Combine like terms: 3.232645975 + 2.5 = 5.732645975 x = 5.732645975 Simplifying x = 5.732645975

Subproblem 2

x + -2.5 = -3.232645975 Simplifying x + -2.5 = -3.232645975 Reorder the terms: -2.5 + x = -3.232645975 Solving -2.5 + x = -3.232645975 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2.5' to each side of the equation. -2.5 + 2.5 + x = -3.232645975 + 2.5 Combine like terms: -2.5 + 2.5 = 0.0 0.0 + x = -3.232645975 + 2.5 x = -3.232645975 + 2.5 Combine like terms: -3.232645975 + 2.5 = -0.732645975 x = -0.732645975 Simplifying x = -0.732645975

Solution

The solution to the problem is based on the solutions from the subproblems. x = {5.732645975, -0.732645975}

See similar equations:

| 15t^2+19t+6=0 | | 4x+40-6x=1-8x+3 | | 3(x-4)+60=-3x | | ln(4x-1)+ln(x+2)=2lnx | | 3x^2-7=2 | | 20d/d= | | 4x+10=-32-3x | | 7x-7=-27+3x | | 0.5(4x+12)=3 | | 40.5+.40x+.40x=x | | 0.5x+1=1.5x-2 | | yk+yz=z | | 12x-4-(8x+3)+(7x-2)= | | 5(3x-4)+2(17-5x)-2(2x+3)=-3 | | 3(3x+10)=1 | | 3(3x+10)=12 | | 39-3x=49-8x | | 17ln(x)=40 | | 7x=3y-6 | | 5x+7=-25-3x | | l=32+1.2t | | 5x+11y=44 | | 40.5+.45x+.40x=x | | -2*-.5+6=Y | | 2y^2+3y-9= | | -15x+16=85-29x | | 2x-4+4x-40+x=180 | | 6+9x=6+x | | 4x+119=6x+151 | | 4x-32=3x-9 | | 35-4x=5-10x | | 5x+12=-36-3x |

Equations solver categories