-3n < 81...divide both sides by -3, change the inequality sign
n > -81/3
n > - 27 <==
** in an inequality, when dividing/multiplying by a negative number, the inequality sign changes
The answer is to be 1.283.1
Plug in 120,000 for “C”
Therefore 120,000 = 2.32N + 34,180 and solve for “N”
Simple algebra, subtract 34180 from both sides:
85,820 = 2.32N
Divide both sides by 2.32:
N = 36,991.38
Answer:
First part:
Set h(t) = 231and solve for t.
-16t²+ 152t + 9= 231
-16t² + 152t - 222= 0
Solve this quadratic equation for t. You should get 2 positive solutions. The lower value is the time to reach 231 on the way up, and the higher value is the time to reach 231 again, on the way down.
Second part:
Set h(t) = 0 and solve the resulting quadratic equation for t. You should get a negative solution (which you can discard), and a positive solution. The latter is your answer.