2k^2+5k-9=0

Simple and best practice solution for 2k^2+5k-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 2k^2+5k-9=0 equation:


Simplifying
2k2 + 5k + -9 = 0

Reorder the terms:
-9 + 5k + 2k2 = 0

Solving
-9 + 5k + 2k2 = 0

Solving for variable 'k'.

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

Divide each side by '2'.
-4.5 + 2.5k + k2 = 0

Move the constant term to the right:

Add '4.5' to each side of the equation.
-4.5 + 2.5k + 4.5 + k2 = 0 + 4.5

Reorder the terms:
-4.5 + 4.5 + 2.5k + k2 = 0 + 4.5

Combine like terms: -4.5 + 4.5 = 0.0
0.0 + 2.5k + k2 = 0 + 4.5
2.5k + k2 = 0 + 4.5

Combine like terms: 0 + 4.5 = 4.5
2.5k + k2 = 4.5

The k term is 2.5k.  Take half its coefficient (1.25).
Square it (1.5625) and add it to both sides.

Add '1.5625' to each side of the equation.
2.5k + 1.5625 + k2 = 4.5 + 1.5625

Reorder the terms:
1.5625 + 2.5k + k2 = 4.5 + 1.5625

Combine like terms: 4.5 + 1.5625 = 6.0625
1.5625 + 2.5k + k2 = 6.0625

Factor a perfect square on the left side:
(k + 1.25)(k + 1.25) = 6.0625

Calculate the square root of the right side: 2.46221445

Break this problem into two subproblems by setting 
(k + 1.25) equal to 2.46221445 and -2.46221445.

Subproblem 1

k + 1.25 = 2.46221445 Simplifying k + 1.25 = 2.46221445 Reorder the terms: 1.25 + k = 2.46221445 Solving 1.25 + k = 2.46221445 Solving for variable 'k'. Move all terms containing k to the left, all other terms to the right. Add '-1.25' to each side of the equation. 1.25 + -1.25 + k = 2.46221445 + -1.25 Combine like terms: 1.25 + -1.25 = 0.00 0.00 + k = 2.46221445 + -1.25 k = 2.46221445 + -1.25 Combine like terms: 2.46221445 + -1.25 = 1.21221445 k = 1.21221445 Simplifying k = 1.21221445

Subproblem 2

k + 1.25 = -2.46221445 Simplifying k + 1.25 = -2.46221445 Reorder the terms: 1.25 + k = -2.46221445 Solving 1.25 + k = -2.46221445 Solving for variable 'k'. Move all terms containing k to the left, all other terms to the right. Add '-1.25' to each side of the equation. 1.25 + -1.25 + k = -2.46221445 + -1.25 Combine like terms: 1.25 + -1.25 = 0.00 0.00 + k = -2.46221445 + -1.25 k = -2.46221445 + -1.25 Combine like terms: -2.46221445 + -1.25 = -3.71221445 k = -3.71221445 Simplifying k = -3.71221445

Solution

The solution to the problem is based on the solutions from the subproblems. k = {1.21221445, -3.71221445}

See similar equations:

| 7+5=4x+12-8 | | 10+6x(20-5)= | | y=-5+8x+x^2 | | 8-3(i-4)= | | ln(30)=ln(x)+ln(x+1) | | (x+7)3= | | 8x^2-16x-46=0 | | 2x+12=-x | | 3(x-3)=.4x+40 | | 4x+3+10x-5=180 | | -6.5+15=9.7+43.8 | | 5(2z-2)=45+5 | | 5(2x-2)=45 | | -18.5=x-(-4.6) | | x^6+4x^4-32x^2=0 | | 25x^2=20x+6 | | 8x^2+4x=60 | | 2d+3=-2 | | 32*n=150 | | -20=-4z-8 | | 10a+5(q-3)=15 | | rx^3+5x^2+4x+20=0 | | 5x+2(3x-1)=31 | | 18y=z | | 3w-8=-17 | | (x-12)(x-6)=0 | | 5a+(12a-32)=4+13a | | 1-2x^3-9x^2-12x=0 | | 8(x-4)= | | (4y-9)(6-y)=0 | | A=3.14(2) | | 9a+30a+16=0 |

Equations solver categories