7b^2+2b-1=4

Solution for 7b^2+2b-1=4 equation:

Simplifying
7b2 + 2b + -1 = 4

Reorder the terms:
-1 + 2b + 7b2 = 4

Solving
-1 + 2b + 7b2 = 4

Solving for variable 'b'.

Reorder the terms:
-1 + -4 + 2b + 7b2 = 4 + -4

Combine like terms: -1 + -4 = -5
-5 + 2b + 7b2 = 4 + -4

Combine like terms: 4 + -4 = 0
-5 + 2b + 7b2 = 0

Factor a trinomial.
(-1 + -1b)(5 + -7b) = 0

Subproblem 1
Set the factor '(-1 + -1b)' equal to zero and attempt to solve:

Simplifying
-1 + -1b = 0

Solving
-1 + -1b = 0

Move all terms containing b to the left, all other terms to the right.

Add '1' to each side of the equation.
-1 + 1 + -1b = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -1b = 0 + 1
-1b = 0 + 1

Combine like terms: 0 + 1 = 1
-1b = 1

Divide each side by '-1'.
b = -1

Simplifying
b = -1
Subproblem 2
Set the factor '(5 + -7b)' equal to zero and attempt to solve:

Simplifying
5 + -7b = 0

Solving
5 + -7b = 0

Move all terms containing b to the left, all other terms to the right.

Add '-5' to each side of the equation.
5 + -5 + -7b = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -7b = 0 + -5
-7b = 0 + -5

Combine like terms: 0 + -5 = -5
-7b = -5

Divide each side by '-7'.
b = 0.7142857143

Simplifying
b = 0.7142857143
Solution
b = {-1, 0.7142857143}