7x^2+15x-20=0

Simple and best practice solution for 7x^2+15x-20=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 7x^2+15x-20=0 equation:


Simplifying
7x2 + 15x + -20 = 0

Reorder the terms:
-20 + 15x + 7x2 = 0

Solving
-20 + 15x + 7x2 = 0

Solving for variable 'x'.

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

Divide each side by '7'.
-2.857142857 + 2.142857143x + x2 = 0

Move the constant term to the right:

Add '2.857142857' to each side of the equation.
-2.857142857 + 2.142857143x + 2.857142857 + x2 = 0 + 2.857142857

Reorder the terms:
-2.857142857 + 2.857142857 + 2.142857143x + x2 = 0 + 2.857142857

Combine like terms: -2.857142857 + 2.857142857 = 0.000000000
0.000000000 + 2.142857143x + x2 = 0 + 2.857142857
2.142857143x + x2 = 0 + 2.857142857

Combine like terms: 0 + 2.857142857 = 2.857142857
2.142857143x + x2 = 2.857142857

The x term is 2.142857143x.  Take half its coefficient (1.071428572).
Square it (1.147959185) and add it to both sides.

Add '1.147959185' to each side of the equation.
2.142857143x + 1.147959185 + x2 = 2.857142857 + 1.147959185

Reorder the terms:
1.147959185 + 2.142857143x + x2 = 2.857142857 + 1.147959185

Combine like terms: 2.857142857 + 1.147959185 = 4.005102042
1.147959185 + 2.142857143x + x2 = 4.005102042

Factor a perfect square on the left side:
(x + 1.071428572)(x + 1.071428572) = 4.005102042

Calculate the square root of the right side: 2.001275104

Break this problem into two subproblems by setting 
(x + 1.071428572) equal to 2.001275104 and -2.001275104.

Subproblem 1

x + 1.071428572 = 2.001275104 Simplifying x + 1.071428572 = 2.001275104 Reorder the terms: 1.071428572 + x = 2.001275104 Solving 1.071428572 + x = 2.001275104 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.071428572' to each side of the equation. 1.071428572 + -1.071428572 + x = 2.001275104 + -1.071428572 Combine like terms: 1.071428572 + -1.071428572 = 0.000000000 0.000000000 + x = 2.001275104 + -1.071428572 x = 2.001275104 + -1.071428572 Combine like terms: 2.001275104 + -1.071428572 = 0.929846532 x = 0.929846532 Simplifying x = 0.929846532

Subproblem 2

x + 1.071428572 = -2.001275104 Simplifying x + 1.071428572 = -2.001275104 Reorder the terms: 1.071428572 + x = -2.001275104 Solving 1.071428572 + x = -2.001275104 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.071428572' to each side of the equation. 1.071428572 + -1.071428572 + x = -2.001275104 + -1.071428572 Combine like terms: 1.071428572 + -1.071428572 = 0.000000000 0.000000000 + x = -2.001275104 + -1.071428572 x = -2.001275104 + -1.071428572 Combine like terms: -2.001275104 + -1.071428572 = -3.072703676 x = -3.072703676 Simplifying x = -3.072703676

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.929846532, -3.072703676}

See similar equations:

| 4x^2+11x+5=0 | | 12x^2-39x+14=0 | | -x+6x+5=7x-7 | | 12x^2-39x+24=0 | | 12x^2-39x+40=0 | | 2(3x+2)=-32 | | 4z^4-4z^3+5z^2-4z+1=0 | | 1200=1.5x+1.5x+x | | -6D+1=4D+21 | | 6x^2+60x+150=0 | | 20=9x+2 | | 3[2x+3(2x+1)]=105 | | 7(7-6)2= | | y=-3+9 | | 3(2-7)+6= | | (4x+9)(3x^2+4x+2)= | | -2(5v-7)=-8(v+2) | | 8=2(1+1) | | 8x=60 | | 3x-3.2=2.8 | | 7x+3(x-7)-4(x-7)= | | 8y+20+3y+3=34 | | 6(-11)-5(3)= | | 4x^2+6x-9x^2=7 | | y/4=8/16 | | 15x+2=16x-3 | | -16a=75-a | | (8x+4)2=-40 | | 5x+1=6x-5 | | (5x+6)(2x-1)=0 | | 5x(7)+10x(6)-15x(5)+10x(4)= | | 4x^2-101x+25=0 |

Equations solver categories