.81x^2-1.4x-1=0

Simple and best practice solution for .81x^2-1.4x-1=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 .81x^2-1.4x-1=0 equation:


Simplifying
0.81x2 + -1.4x + -1 = 0

Reorder the terms:
-1 + -1.4x + 0.81x2 = 0

Solving
-1 + -1.4x + 0.81x2 = 0

Solving for variable 'x'.

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

Divide each side by '0.81'.
-1.234567901 + -1.728395062x + x2 = 0

Move the constant term to the right:

Add '1.234567901' to each side of the equation.
-1.234567901 + -1.728395062x + 1.234567901 + x2 = 0 + 1.234567901

Reorder the terms:
-1.234567901 + 1.234567901 + -1.728395062x + x2 = 0 + 1.234567901

Combine like terms: -1.234567901 + 1.234567901 = 0.000000000
0.000000000 + -1.728395062x + x2 = 0 + 1.234567901
-1.728395062x + x2 = 0 + 1.234567901

Combine like terms: 0 + 1.234567901 = 1.234567901
-1.728395062x + x2 = 1.234567901

The x term is -1.728395062x.  Take half its coefficient (-0.864197531).
Square it (0.7468373726) and add it to both sides.

Add '0.7468373726' to each side of the equation.
-1.728395062x + 0.7468373726 + x2 = 1.234567901 + 0.7468373726

Reorder the terms:
0.7468373726 + -1.728395062x + x2 = 1.234567901 + 0.7468373726

Combine like terms: 1.234567901 + 0.7468373726 = 1.9814052736
0.7468373726 + -1.728395062x + x2 = 1.9814052736

Factor a perfect square on the left side:
(x + -0.864197531)(x + -0.864197531) = 1.9814052736

Calculate the square root of the right side: 1.407623982

Break this problem into two subproblems by setting 
(x + -0.864197531) equal to 1.407623982 and -1.407623982.

Subproblem 1

x + -0.864197531 = 1.407623982 Simplifying x + -0.864197531 = 1.407623982 Reorder the terms: -0.864197531 + x = 1.407623982 Solving -0.864197531 + x = 1.407623982 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.864197531' to each side of the equation. -0.864197531 + 0.864197531 + x = 1.407623982 + 0.864197531 Combine like terms: -0.864197531 + 0.864197531 = 0.000000000 0.000000000 + x = 1.407623982 + 0.864197531 x = 1.407623982 + 0.864197531 Combine like terms: 1.407623982 + 0.864197531 = 2.271821513 x = 2.271821513 Simplifying x = 2.271821513

Subproblem 2

x + -0.864197531 = -1.407623982 Simplifying x + -0.864197531 = -1.407623982 Reorder the terms: -0.864197531 + x = -1.407623982 Solving -0.864197531 + x = -1.407623982 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.864197531' to each side of the equation. -0.864197531 + 0.864197531 + x = -1.407623982 + 0.864197531 Combine like terms: -0.864197531 + 0.864197531 = 0.000000000 0.000000000 + x = -1.407623982 + 0.864197531 x = -1.407623982 + 0.864197531 Combine like terms: -1.407623982 + 0.864197531 = -0.543426451 x = -0.543426451 Simplifying x = -0.543426451

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.271821513, -0.543426451}

See similar equations:

| y=0.6x+45 | | 25u^2-v^2=0 | | 8.25+.25=7610.75 | | -7x^2-x+8=0 | | 5z+z=5z-1 | | 0.4z-5=3 | | x^4+12x^3+11x^2=0 | | (8+6)*8=(7+x)*7 | | 2(x-9)+x=3(x-7)+3 | | 8.25+.25=10.75 | | -a^2-8a+48=0 | | 6*6=4*x | | -w^2-2w+15=0 | | 3x-4=6x-4 | | 1.2+6x=-0.6 | | (2/5)c+4-(1/5)c=-9 | | 5a-2(3a+7)=200 | | C=8(y+3) | | h+3.7=12.2 | | 14*x=10*21 | | 2f+10=f+18 | | -11=3t+-2 | | 9x-9=3x+16 | | a^2-2ab-8b^2=0 | | -2+(3)=x | | 3x^4-7x^3+16x^2-28x+16=0 | | 2y+2w= | | -b^2-5b+24=0 | | y=e^5 | | f(x)=x^2-4x+53 | | ax(bxc)=b(a*c)-c(a*b) | | y=e^1 |

Equations solver categories