21t^2-18t-3=0

Solution for 21t^2-18t-3=0 equation:

Simplifying
21t2 + -18t + -3 = 0

Reorder the terms:
-3 + -18t + 21t2 = 0

Solving
-3 + -18t + 21t2 = 0

Solving for variable 't'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-1 + -6t + 7t2) = 0

Factor a trinomial.
3((-1 + -7t)(1 + -1t)) = 0

Ignore the factor 3.
Subproblem 1
Set the factor '(-1 + -7t)' equal to zero and attempt to solve:

Simplifying
-1 + -7t = 0

Solving
-1 + -7t = 0

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

Add '1' to each side of the equation.
-1 + 1 + -7t = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -7t = 0 + 1
-7t = 0 + 1

Combine like terms: 0 + 1 = 1
-7t = 1

Divide each side by '-7'.
t = -0.1428571429

Simplifying
t = -0.1428571429
Subproblem 2
Set the factor '(1 + -1t)' equal to zero and attempt to solve:

Simplifying
1 + -1t = 0

Solving
1 + -1t = 0

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

Add '-1' to each side of the equation.
1 + -1 + -1t = 0 + -1

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

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

Divide each side by '-1'.
t = 1

Simplifying
t = 1
Solution
t = {-0.1428571429, 1}