18=4t^2-21t

Solution for 18=4t^2-21t equation:

Simplifying
18 = 4t2 + -21t

Reorder the terms:
18 = -21t + 4t2

Solving
18 = -21t + 4t2

Solving for variable 't'.

Reorder the terms:
18 + 21t + -4t2 = -21t + 21t + 4t2 + -4t2

Combine like terms: -21t + 21t = 0
18 + 21t + -4t2 = 0 + 4t2 + -4t2
18 + 21t + -4t2 = 4t2 + -4t2

Combine like terms: 4t2 + -4t2 = 0
18 + 21t + -4t2 = 0

Factor a trinomial.
(6 + -1t)(3 + 4t) = 0

Subproblem 1
Set the factor '(6 + -1t)' equal to zero and attempt to solve:

Simplifying
6 + -1t = 0

Solving
6 + -1t = 0

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

Add '-6' to each side of the equation.
6 + -6 + -1t = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -1t = 0 + -6
-1t = 0 + -6

Combine like terms: 0 + -6 = -6
-1t = -6

Divide each side by '-1'.
t = 6

Simplifying
t = 6
Subproblem 2
Set the factor '(3 + 4t)' equal to zero and attempt to solve:

Simplifying
3 + 4t = 0

Solving
3 + 4t = 0

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

Add '-3' to each side of the equation.
3 + -3 + 4t = 0 + -3

Combine like terms: 3 + -3 = 0
0 + 4t = 0 + -3
4t = 0 + -3

Combine like terms: 0 + -3 = -3
4t = -3

Divide each side by '4'.
t = -0.75

Simplifying
t = -0.75
Solution
t = {6, -0.75}