21x^2+2x=17

Simple and best practice solution for 21x^2+2x=17 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 21x^2+2x=17 equation:


Simplifying
21x2 + 2x = 17

Reorder the terms:
2x + 21x2 = 17

Solving
2x + 21x2 = 17

Solving for variable 'x'.

Reorder the terms:
-17 + 2x + 21x2 = 17 + -17

Combine like terms: 17 + -17 = 0
-17 + 2x + 21x2 = 0

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

Divide each side by '21'.
-0.8095238095 + 0.09523809524x + x2 = 0

Move the constant term to the right:

Add '0.8095238095' to each side of the equation.
-0.8095238095 + 0.09523809524x + 0.8095238095 + x2 = 0 + 0.8095238095

Reorder the terms:
-0.8095238095 + 0.8095238095 + 0.09523809524x + x2 = 0 + 0.8095238095

Combine like terms: -0.8095238095 + 0.8095238095 = 0.0000000000
0.0000000000 + 0.09523809524x + x2 = 0 + 0.8095238095
0.09523809524x + x2 = 0 + 0.8095238095

Combine like terms: 0 + 0.8095238095 = 0.8095238095
0.09523809524x + x2 = 0.8095238095

The x term is 0.09523809524x.  Take half its coefficient (0.04761904762).
Square it (0.002267573696) and add it to both sides.

Add '0.002267573696' to each side of the equation.
0.09523809524x + 0.002267573696 + x2 = 0.8095238095 + 0.002267573696

Reorder the terms:
0.002267573696 + 0.09523809524x + x2 = 0.8095238095 + 0.002267573696

Combine like terms: 0.8095238095 + 0.002267573696 = 0.811791383196
0.002267573696 + 0.09523809524x + x2 = 0.811791383196

Factor a perfect square on the left side:
(x + 0.04761904762)(x + 0.04761904762) = 0.811791383196

Calculate the square root of the right side: 0.900994663

Break this problem into two subproblems by setting 
(x + 0.04761904762) equal to 0.900994663 and -0.900994663.

Subproblem 1

x + 0.04761904762 = 0.900994663 Simplifying x + 0.04761904762 = 0.900994663 Reorder the terms: 0.04761904762 + x = 0.900994663 Solving 0.04761904762 + x = 0.900994663 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.04761904762' to each side of the equation. 0.04761904762 + -0.04761904762 + x = 0.900994663 + -0.04761904762 Combine like terms: 0.04761904762 + -0.04761904762 = 0.00000000000 0.00000000000 + x = 0.900994663 + -0.04761904762 x = 0.900994663 + -0.04761904762 Combine like terms: 0.900994663 + -0.04761904762 = 0.85337561538 x = 0.85337561538 Simplifying x = 0.85337561538

Subproblem 2

x + 0.04761904762 = -0.900994663 Simplifying x + 0.04761904762 = -0.900994663 Reorder the terms: 0.04761904762 + x = -0.900994663 Solving 0.04761904762 + x = -0.900994663 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.04761904762' to each side of the equation. 0.04761904762 + -0.04761904762 + x = -0.900994663 + -0.04761904762 Combine like terms: 0.04761904762 + -0.04761904762 = 0.00000000000 0.00000000000 + x = -0.900994663 + -0.04761904762 x = -0.900994663 + -0.04761904762 Combine like terms: -0.900994663 + -0.04761904762 = -0.94861371062 x = -0.94861371062 Simplifying x = -0.94861371062

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.85337561538, -0.94861371062}

See similar equations:

| x-(0.1)=14 | | 10+14x+20+16x+20=180 | | -3(12-4x)=-24 | | 10-5=60 | | S=18w+8 | | x-0.1=14 | | 31+2x-15+x-7=180 | | 21+3x-x^2=12 | | 4x^2+25y^2= | | 12-x-7=-2 | | 11r+10=-7r-19-11r | | 2+13x=6x+23 | | 2x-4(x-3)=-2+5x-7 | | 8x^2+20x=12x | | h=3-10g | | -1+x=-18 | | g=-7.1 | | Y=t^3-12t+1 | | (x^2-x+9)=(x^2+x+15) | | -10=m+-15 | | 5(m+2)+(m+1)=40 | | 5x+8y=2600 | | 5x+8y=2609 | | 5(x+1)=3(x+2)+11 | | 8=8p+79-3p | | x^2-(3x)+21=12 | | 8u= | | 4h^2+8h+3=0 | | X^5-3x^3-4x=o | | 2x(3x-4)-3x(2x+5)=7 | | 75-3x^2= | | -8x+3=351 |

Equations solver categories