7r^2-8r-10=0

Simple and best practice solution for 7r^2-8r-10=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 7r^2-8r-10=0 equation:


Simplifying
7r2 + -8r + -10 = 0

Reorder the terms:
-10 + -8r + 7r2 = 0

Solving
-10 + -8r + 7r2 = 0

Solving for variable 'r'.

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

Divide each side by '7'.
-1.428571429 + -1.142857143r + r2 = 0

Move the constant term to the right:

Add '1.428571429' to each side of the equation.
-1.428571429 + -1.142857143r + 1.428571429 + r2 = 0 + 1.428571429

Reorder the terms:
-1.428571429 + 1.428571429 + -1.142857143r + r2 = 0 + 1.428571429

Combine like terms: -1.428571429 + 1.428571429 = 0.000000000
0.000000000 + -1.142857143r + r2 = 0 + 1.428571429
-1.142857143r + r2 = 0 + 1.428571429

Combine like terms: 0 + 1.428571429 = 1.428571429
-1.142857143r + r2 = 1.428571429

The r term is -1.142857143r.  Take half its coefficient (-0.5714285715).
Square it (0.3265306123) and add it to both sides.

Add '0.3265306123' to each side of the equation.
-1.142857143r + 0.3265306123 + r2 = 1.428571429 + 0.3265306123

Reorder the terms:
0.3265306123 + -1.142857143r + r2 = 1.428571429 + 0.3265306123

Combine like terms: 1.428571429 + 0.3265306123 = 1.7551020413
0.3265306123 + -1.142857143r + r2 = 1.7551020413

Factor a perfect square on the left side:
(r + -0.5714285715)(r + -0.5714285715) = 1.7551020413

Calculate the square root of the right side: 1.324802642

Break this problem into two subproblems by setting 
(r + -0.5714285715) equal to 1.324802642 and -1.324802642.

Subproblem 1

r + -0.5714285715 = 1.324802642 Simplifying r + -0.5714285715 = 1.324802642 Reorder the terms: -0.5714285715 + r = 1.324802642 Solving -0.5714285715 + r = 1.324802642 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '0.5714285715' to each side of the equation. -0.5714285715 + 0.5714285715 + r = 1.324802642 + 0.5714285715 Combine like terms: -0.5714285715 + 0.5714285715 = 0.0000000000 0.0000000000 + r = 1.324802642 + 0.5714285715 r = 1.324802642 + 0.5714285715 Combine like terms: 1.324802642 + 0.5714285715 = 1.8962312135 r = 1.8962312135 Simplifying r = 1.8962312135

Subproblem 2

r + -0.5714285715 = -1.324802642 Simplifying r + -0.5714285715 = -1.324802642 Reorder the terms: -0.5714285715 + r = -1.324802642 Solving -0.5714285715 + r = -1.324802642 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '0.5714285715' to each side of the equation. -0.5714285715 + 0.5714285715 + r = -1.324802642 + 0.5714285715 Combine like terms: -0.5714285715 + 0.5714285715 = 0.0000000000 0.0000000000 + r = -1.324802642 + 0.5714285715 r = -1.324802642 + 0.5714285715 Combine like terms: -1.324802642 + 0.5714285715 = -0.7533740705 r = -0.7533740705 Simplifying r = -0.7533740705

Solution

The solution to the problem is based on the solutions from the subproblems. r = {1.8962312135, -0.7533740705}

See similar equations:

| -53-6x=x+52 | | -8(7-4m+n)= | | (x-2)(x-3)-(x-1)(x-4)=0 | | ln(c-2y)=1 | | 8a+5b=22 | | 5x-68=12x+37 | | 33-10+8g=111 | | x+1(3x-2)=5x-4(3x+2) | | 6k-(7-6k)= | | -8q=6+5q-3 | | 8d+2d-3d+4=6d | | 2x-17=19+5x | | 3y/4-y/2=10 | | ln(y-b)=5t | | -x-18=10-3x | | -27-5x=-7x+9 | | -1-9=8x+6-7x | | -7p+2=107 | | 57+6x=-218-5x | | 4v^2-3v-19=0 | | -1.6+2x^2=180 | | 8x-6x+192=8x+84 | | lny=-t+5 | | 8x-29=11x+55 | | 1-5x-3x=17 | | 21z-35=20x-45 | | a/2+7=1 | | 8d+12-b=8+7b+4 | | -29-11x=-7x+31 | | 1-2+(-12)= | | 3(5x+3)-25=12x+2 | | 2a+3b+6c=54 |

Equations solver categories