2x^2+x+8=78

Simple and best practice solution for 2x^2+x+8=78 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 2x^2+x+8=78 equation:


Simplifying
2x2 + x + 8 = 78

Reorder the terms:
8 + x + 2x2 = 78

Solving
8 + x + 2x2 = 78

Solving for variable 'x'.

Reorder the terms:
8 + -78 + x + 2x2 = 78 + -78

Combine like terms: 8 + -78 = -70
-70 + x + 2x2 = 78 + -78

Combine like terms: 78 + -78 = 0
-70 + x + 2x2 = 0

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

Divide each side by '2'.
-35 + 0.5x + x2 = 0

Move the constant term to the right:

Add '35' to each side of the equation.
-35 + 0.5x + 35 + x2 = 0 + 35

Reorder the terms:
-35 + 35 + 0.5x + x2 = 0 + 35

Combine like terms: -35 + 35 = 0
0 + 0.5x + x2 = 0 + 35
0.5x + x2 = 0 + 35

Combine like terms: 0 + 35 = 35
0.5x + x2 = 35

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
0.5x + 0.25 + x2 = 35 + 0.25

Reorder the terms:
0.25 + 0.5x + x2 = 35 + 0.25

Combine like terms: 35 + 0.25 = 35.25
0.25 + 0.5x + x2 = 35.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 35.25

Calculate the square root of the right side: 5.937171044

Break this problem into two subproblems by setting 
(x + 0.5) equal to 5.937171044 and -5.937171044.

Subproblem 1

x + 0.5 = 5.937171044 Simplifying x + 0.5 = 5.937171044 Reorder the terms: 0.5 + x = 5.937171044 Solving 0.5 + x = 5.937171044 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 5.937171044 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 5.937171044 + -0.5 x = 5.937171044 + -0.5 Combine like terms: 5.937171044 + -0.5 = 5.437171044 x = 5.437171044 Simplifying x = 5.437171044

Subproblem 2

x + 0.5 = -5.937171044 Simplifying x + 0.5 = -5.937171044 Reorder the terms: 0.5 + x = -5.937171044 Solving 0.5 + x = -5.937171044 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -5.937171044 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -5.937171044 + -0.5 x = -5.937171044 + -0.5 Combine like terms: -5.937171044 + -0.5 = -6.437171044 x = -6.437171044 Simplifying x = -6.437171044

Solution

The solution to the problem is based on the solutions from the subproblems. x = {5.437171044, -6.437171044}

See similar equations:

| -4x^2-20x-21=0 | | (u^2)-2u-21=0 | | 8x^2-44x+56=0 | | 208=6*8*w | | 3x^2+24=240 | | x+1/3=6(1/4) | | 10-2f=8 | | 2(2k+1)-36= | | 12-14x=7x+45 | | 6x+8y=1400 | | x/3+4=5+2 | | w+w+78=478 | | 9/14-1/7 | | 6*x=10+x*5 | | 9(2/3)+2(4/7) | | m+m=3600 | | 168=v+v-1 | | -5+6/2+7 | | 7(-3x-8)=70 | | 5-10sin(7x)=0 | | 5/-9*-3/8*-2 | | 7(3x-8)=70 | | 72+4x/9x^1/2 | | h+h-5=44 | | x/7+x/2=9/7 | | 7u+3=-2(u-6) | | -5(w-2)=-3w+18 | | -5(w-21)=-3w+18 | | -3u-15=3(u+7) | | (10p^3-5)/(p+1)=0 | | 8=c/7+5 | | 13v=7(p-v) |

Equations solver categories