show working of the following
1. Suzie works in a boutique. Each month, her earnings, E dollars, are given by the formula E = 2500 + 0.105,wheresdollars are her sales for the month. One month, Suzie's sales were $8000. How much did she earn that month? Bonnie wants to install a laminate oor in a room that measures 5.0 In by 3.0 In. The ooring comes in bundles. Each bundle costs $47.76 and covers an area of 2.23 ml. Determine the cost of the ooring. Houd plans to replace the light bulbs in his house with energy-saver light bulbs. The formula C = 0.006]: + 0.45 gives the cost, C dollars. of using a regular bulb for h hours. The cost for an energy-saver bulb is C = 0.004h + 1.05. How much money does Houd save with the energy saver bulb after 1000 h of use? 4. The formula E = Pt gives the energy, E watt hours, used when an electrical appliance of power P watts is used for t hours. Determine the energy used in each situation. a} A 17-W uorescent bulb is left on for I h. b) A MOO-W blow dryer is used for 10 min. c) How long would the uorescent bulb need to be left on so that it consumes as much energy as using the blow dryer for 10 min? 5. The circumference, C, of a circle with diameter dis C = nd. a) Solve the formula for d. h) Calculate the diameter of a circie with circumference 8 m. 8. The power in an electrical circuit is given by the formula P = PR, where P is the power in watts, I is the current in amperes, and R is the resistance in ohms. Determine R when P = 1000 W and I = 12 A. Explain your method. 7.. The aspect ratio of a hang glider describes its performance during ight. The formula 2 R = s: . gives the aspect ratio, R, for a hang glider with wingspan s and wing area A. 31 Rearrange the formula to isolate 3. Use an arrow diagram to show the inverse operations you can use. b) lake wants to design a hang glider with an aspect ratio of 2.7 and a wing area of 30 square feet. What will be the wingspan of the glider? B. The formula A = P(1 + rt) gives the amount, A dollars, of a simple interest investment. In the formula, P dollars is the principal invested, r is the annual interest rate expressed as a decimal, and t is the number of years. a) Solve the formula for P. b) The amount of a simple interest investment is $2000 after 3.5 years. The principal earned 5% interest per year. Calculate the principal invested. 9. Evaluate without a calculator. a) 52 b) s-2 c) (5)2 Explain how you know whether the sign of the answer is positive or negative. 10. Simplify, then evaluate. 2 3 76 a) 10 X10 b) F 3 2 c) (1.122)! a) 2 :52 For which parts did you use a calculator? Explain. 11. Simplify using the exponent rules. a) k413k-31-2 b) (a5 ) -2 ( a3 ) 4 - 3 () xy 12. Evaluate when c = 5 and d = -3. a) ed b) do ( ) cd3 o'd d) (2cd2)3 13. Evaluate. a) 162 b) (-27)3 c) 325 5 3 d) 83 e) 6254 f) 0.812
