(3x-4)(x+3)=15

Simple and best practice solution for (3x-4)(x+3)=15 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 (3x-4)(x+3)=15 equation:


Simplifying
(3x + -4)(x + 3) = 15

Reorder the terms:
(-4 + 3x)(x + 3) = 15

Reorder the terms:
(-4 + 3x)(3 + x) = 15

Multiply (-4 + 3x) * (3 + x)
(-4(3 + x) + 3x * (3 + x)) = 15
((3 * -4 + x * -4) + 3x * (3 + x)) = 15
((-12 + -4x) + 3x * (3 + x)) = 15
(-12 + -4x + (3 * 3x + x * 3x)) = 15
(-12 + -4x + (9x + 3x2)) = 15

Combine like terms: -4x + 9x = 5x
(-12 + 5x + 3x2) = 15

Solving
-12 + 5x + 3x2 = 15

Solving for variable 'x'.

Reorder the terms:
-12 + -15 + 5x + 3x2 = 15 + -15

Combine like terms: -12 + -15 = -27
-27 + 5x + 3x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-27 + 5x + 3x2 = 0

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

Divide each side by '3'.
-9 + 1.666666667x + x2 = 0

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + 1.666666667x + 9 + x2 = 0 + 9

Reorder the terms:
-9 + 9 + 1.666666667x + x2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + 1.666666667x + x2 = 0 + 9
1.666666667x + x2 = 0 + 9

Combine like terms: 0 + 9 = 9
1.666666667x + x2 = 9

The x term is 1.666666667x.  Take half its coefficient (0.8333333335).
Square it (0.6944444447) and add it to both sides.

Add '0.6944444447' to each side of the equation.
1.666666667x + 0.6944444447 + x2 = 9 + 0.6944444447

Reorder the terms:
0.6944444447 + 1.666666667x + x2 = 9 + 0.6944444447

Combine like terms: 9 + 0.6944444447 = 9.6944444447
0.6944444447 + 1.666666667x + x2 = 9.6944444447

Factor a perfect square on the left side:
(x + 0.8333333335)(x + 0.8333333335) = 9.6944444447

Calculate the square root of the right side: 3.113590282

Break this problem into two subproblems by setting 
(x + 0.8333333335) equal to 3.113590282 and -3.113590282.

Subproblem 1

x + 0.8333333335 = 3.113590282 Simplifying x + 0.8333333335 = 3.113590282 Reorder the terms: 0.8333333335 + x = 3.113590282 Solving 0.8333333335 + x = 3.113590282 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.8333333335' to each side of the equation. 0.8333333335 + -0.8333333335 + x = 3.113590282 + -0.8333333335 Combine like terms: 0.8333333335 + -0.8333333335 = 0.0000000000 0.0000000000 + x = 3.113590282 + -0.8333333335 x = 3.113590282 + -0.8333333335 Combine like terms: 3.113590282 + -0.8333333335 = 2.2802569485 x = 2.2802569485 Simplifying x = 2.2802569485

Subproblem 2

x + 0.8333333335 = -3.113590282 Simplifying x + 0.8333333335 = -3.113590282 Reorder the terms: 0.8333333335 + x = -3.113590282 Solving 0.8333333335 + x = -3.113590282 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.8333333335' to each side of the equation. 0.8333333335 + -0.8333333335 + x = -3.113590282 + -0.8333333335 Combine like terms: 0.8333333335 + -0.8333333335 = 0.0000000000 0.0000000000 + x = -3.113590282 + -0.8333333335 x = -3.113590282 + -0.8333333335 Combine like terms: -3.113590282 + -0.8333333335 = -3.9469236155 x = -3.9469236155 Simplifying x = -3.9469236155

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.2802569485, -3.9469236155}

See similar equations:

| -3(x-13)-21=3-6 | | 16r^2-22r+7=0 | | -3y=12-9x | | -150=-6k-6(4-8k) | | 6.4/4= | | 18k^2-8yt+48ky-3kt= | | 7/16-3/16= | | (3-2i)x+3=(4+3i)x-4i | | 7x+9-2x+4=33 | | (7-u)(4u-2)=0 | | 5x/3xy-4/x^2 | | -8v-4(v-3)=96 | | 2x^2+16x-225=0 | | 11x+0.7=1-0.2x | | 4m^2=27m+40 | | 81-3/4x=3/2x | | 3/4v=12 | | 5(x+3)-4x=26 | | 2/3x30=u | | 2=2y+15 | | 6y-4(y-3)+6= | | 147=2+5(1-4x) | | 2/3x30 | | 20x^2-7x-3= | | 1/3v=18 | | 0=9x^2-16x-44 | | 12-3/2x=5/2x | | 13x+271=180 | | 1/4v=16 | | 3/5v=15 | | k+8=-7 | | 12/7=-6y |

Equations solver categories