2² - 5t + 12 = 0
So, because we are solving for t, you must get t isolated! :)
Simplify the equation.
4 - 5t + 12 = 0
Add like terms.
16 - 5t = 0
Subtract 16 from both sides.
-5t = 0 - 16
Simplify.
-5t = -16
Divide both sides by -5.
t = 16/5 OR 3 1/5
~Hope I helped!~