t = 11
Before we can solve this word problem, we have to translate first this problem into numerical form. The sum of fifteen and six times a number t is eighty-one can be translated into
15 + 6t = 81
Let's subtract 15 from both sides of the equation .
15 + 6t - 15 = 81 - 15
6t = 66
Divide both sides of the equation by 6.
6t / 6 = 66 / 6
t = 11
No but use calculator will help with those problems
And its 81 i used the calculator
step-by-step explanation: a reaction is first order. if the initial reactant concentration is 0.0200 m, and 25.0 days later the concentration is 6.25 x 10-4 m, then its half-life is: