8*x^2+7*x-4=0

Simple and best practice solution for 8*x^2+7*x-4=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 8*x^2+7*x-4=0 equation:


Simplifying
8x2 + 7x + -4 = 0

Reorder the terms:
-4 + 7x + 8x2 = 0

Solving
-4 + 7x + 8x2 = 0

Solving for variable 'x'.

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

Divide each side by '8'.
-0.5 + 0.875x + x2 = 0

Move the constant term to the right:

Add '0.5' to each side of the equation.
-0.5 + 0.875x + 0.5 + x2 = 0 + 0.5

Reorder the terms:
-0.5 + 0.5 + 0.875x + x2 = 0 + 0.5

Combine like terms: -0.5 + 0.5 = 0.0
0.0 + 0.875x + x2 = 0 + 0.5
0.875x + x2 = 0 + 0.5

Combine like terms: 0 + 0.5 = 0.5
0.875x + x2 = 0.5

The x term is 0.875x.  Take half its coefficient (0.4375).
Square it (0.19140625) and add it to both sides.

Add '0.19140625' to each side of the equation.
0.875x + 0.19140625 + x2 = 0.5 + 0.19140625

Reorder the terms:
0.19140625 + 0.875x + x2 = 0.5 + 0.19140625

Combine like terms: 0.5 + 0.19140625 = 0.69140625
0.19140625 + 0.875x + x2 = 0.69140625

Factor a perfect square on the left side:
(x + 0.4375)(x + 0.4375) = 0.69140625

Calculate the square root of the right side: 0.831508418

Break this problem into two subproblems by setting 
(x + 0.4375) equal to 0.831508418 and -0.831508418.

Subproblem 1

x + 0.4375 = 0.831508418 Simplifying x + 0.4375 = 0.831508418 Reorder the terms: 0.4375 + x = 0.831508418 Solving 0.4375 + x = 0.831508418 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.4375' to each side of the equation. 0.4375 + -0.4375 + x = 0.831508418 + -0.4375 Combine like terms: 0.4375 + -0.4375 = 0.0000 0.0000 + x = 0.831508418 + -0.4375 x = 0.831508418 + -0.4375 Combine like terms: 0.831508418 + -0.4375 = 0.394008418 x = 0.394008418 Simplifying x = 0.394008418

Subproblem 2

x + 0.4375 = -0.831508418 Simplifying x + 0.4375 = -0.831508418 Reorder the terms: 0.4375 + x = -0.831508418 Solving 0.4375 + x = -0.831508418 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.4375' to each side of the equation. 0.4375 + -0.4375 + x = -0.831508418 + -0.4375 Combine like terms: 0.4375 + -0.4375 = 0.0000 0.0000 + x = -0.831508418 + -0.4375 x = -0.831508418 + -0.4375 Combine like terms: -0.831508418 + -0.4375 = -1.269008418 x = -1.269008418 Simplifying x = -1.269008418

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.394008418, -1.269008418}

See similar equations:

| 8x-4/4=19 | | 3*x^2+6*x+2=0 | | 2h+4=2 | | 30+12(n-1)=120 | | 18x-25=0 | | x^2-8*x+4=0 | | 5*x^2+x-5=0 | | 10x-14=2x+3 | | 9z+(z+2)=10+2z | | TC=30+5Q-2Q^2+4Q^3 | | x^2+3*x-2=0 | | 10x-8+3x^2=0 | | 8x-12=x+3 | | 18-4(x-5)=8(2x+5)-50 | | 2a^2+4-8=-2a^2+4-5 | | 3+25x=20x+7 | | 4*x^2-9*x+3=0 | | x^2+6*x-5=0 | | 1+7x=13+x | | 2x^2+9-6x=0 | | X+3x=360 | | 8-(6x-7)=10-2(24-2x) | | 6n^2-5n+1=0 | | S+12s=-32 | | 3x-7=2(x+5) | | 8-(6x-7)=19-2(24-2x) | | 5*x^2+9*x-3=0 | | 2*x^2+2*x-6=0 | | 2.5x-1.3=1.2x+1.3 | | x^2-20x+200=0 | | 3x-5=39-8x | | x^2+7*x+9=0 |

Equations solver categories