9x^2+21x-9=0

Simple and best practice solution for 9x^2+21x-9=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 9x^2+21x-9=0 equation:


Simplifying
9x2 + 21x + -9 = 0

Reorder the terms:
-9 + 21x + 9x2 = 0

Solving
-9 + 21x + 9x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-3 + 7x + 3x2) = 0

Ignore the factor 3.

Subproblem 1

Set the factor '(-3 + 7x + 3x2)' equal to zero and attempt to solve: Simplifying -3 + 7x + 3x2 = 0 Solving -3 + 7x + 3x2 = 0 Begin completing the square. Divide all terms by 3 the coefficient of the squared term: Divide each side by '3'. -1 + 2.333333333x + x2 = 0 Move the constant term to the right: Add '1' to each side of the equation. -1 + 2.333333333x + 1 + x2 = 0 + 1 Reorder the terms: -1 + 1 + 2.333333333x + x2 = 0 + 1 Combine like terms: -1 + 1 = 0 0 + 2.333333333x + x2 = 0 + 1 2.333333333x + x2 = 0 + 1 Combine like terms: 0 + 1 = 1 2.333333333x + x2 = 1 The x term is 2.333333333x. Take half its coefficient (1.166666667). Square it (1.361111112) and add it to both sides. Add '1.361111112' to each side of the equation. 2.333333333x + 1.361111112 + x2 = 1 + 1.361111112 Reorder the terms: 1.361111112 + 2.333333333x + x2 = 1 + 1.361111112 Combine like terms: 1 + 1.361111112 = 2.361111112 1.361111112 + 2.333333333x + x2 = 2.361111112 Factor a perfect square on the left side: (x + 1.166666667)(x + 1.166666667) = 2.361111112 Calculate the square root of the right side: 1.536590743 Break this problem into two subproblems by setting (x + 1.166666667) equal to 1.536590743 and -1.536590743.

Subproblem 1

x + 1.166666667 = 1.536590743 Simplifying x + 1.166666667 = 1.536590743 Reorder the terms: 1.166666667 + x = 1.536590743 Solving 1.166666667 + x = 1.536590743 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.166666667' to each side of the equation. 1.166666667 + -1.166666667 + x = 1.536590743 + -1.166666667 Combine like terms: 1.166666667 + -1.166666667 = 0.000000000 0.000000000 + x = 1.536590743 + -1.166666667 x = 1.536590743 + -1.166666667 Combine like terms: 1.536590743 + -1.166666667 = 0.369924076 x = 0.369924076 Simplifying x = 0.369924076

Subproblem 2

x + 1.166666667 = -1.536590743 Simplifying x + 1.166666667 = -1.536590743 Reorder the terms: 1.166666667 + x = -1.536590743 Solving 1.166666667 + x = -1.536590743 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.166666667' to each side of the equation. 1.166666667 + -1.166666667 + x = -1.536590743 + -1.166666667 Combine like terms: 1.166666667 + -1.166666667 = 0.000000000 0.000000000 + x = -1.536590743 + -1.166666667 x = -1.536590743 + -1.166666667 Combine like terms: -1.536590743 + -1.166666667 = -2.70325741 x = -2.70325741 Simplifying x = -2.70325741

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.369924076, -2.70325741}

Solution

x = {0.369924076, -2.70325741}

See similar equations:

| 16+(-10)= | | 2ln(5x+2)=24 | | -8+4y=1y-6+3y-2 | | -2(4+5x)-12x=-10(8+x) | | S/4+s/2+s/3=13 | | y=1.76x^2-13.32x+41.00 | | 5x+2(3-x)+1=-15 | | (5/2)x+(1/4)x=(11/4)+x | | 23x+8+6x+3y=0 | | 5-x-2=8+4x | | 3/-7-3= | | 4+x^2=36 | | 5x+2(3-x)+1=-18 | | 8(2n-3)=(7n+7)+8 | | -5/8=-3/8a | | 2(4-x)+2x=-6x-2 | | -5y-7=-4y-9 | | -5y-7=-4y-7 | | (5/4)x+(1/8)x=(9/8)+x | | 2z-9/5+3=2z | | (3/4)(x+3)=9 | | 4.49/2.725 | | 13+x=-2x-3 | | 7=5n-13 | | 5*-1(-1*2)=2*-1-x | | 32=2/3(3x-12) | | (8+10i)(5-8i)= | | 44x^5/8x^3 | | 3x=1+(-8)/x | | 3x-10x/7-6/7=5/4 | | 2x-5+3x=11+4x-6 | | (8+10i)(5-8i)=0 |

Equations solver categories