PRECALCULUS TEST REVIEW 2.7 Solve the inequality. 1. 6x 2 + 5x < 4 2. x 3 −16x ≥ 0 2
3
3. ≤
x +1 x −1
1
1
4.
> x−2 x
5. P dollars invested at interest rate r compounded annually increases to an amount A = P(1 + r)2 in 2 years. An investment of $5000 is to increase to an amount greater than $5500 in 2 years. The interest rate must be greater than what percent? 6. A rectangular playing field with a perimeter of 100 meters is to have an area of at least 500 square meters. Within what bounds must the length of the rectangle lie? 7. A biologist introduces 200 ladybugs into a crop field. The population P of the 1000(1 + 3t)
ladybugs is approximated by the model P =
, where t is the time in days. 5+t
Find the time required for the population to increase to at least 2000 ladybugs.