Intermediate Algebra (11th edition)

SECTION 9.4 Formulas and Further Applications 527

Complete solution available
on the Video Resources on DVD

Concept Check Answer each question in Exercises 1– 4.

1.In solving a formula that has the specified variable in the denominator, what is the first

step?

2.What is the first step in solving a formula like for w?

3.What is the first step in solving a formula like for w?

4.Why is it particularly important to check all proposed solutions to an applied problem

against the information in the original problem?

In Exercises 5 and 6, solve for m in terms of the other variables.

5. 
   
   
   
   6. 
      
   
   
   
   

Solve each equation for the indicated variable. ( Leave in your answers.) See Examples 1

and 2.

7. for t 8. for e 9. for d


8. for d 11. for v 12. for h


9. for r 14. for r 15. for t


10. for r 17. for h 18. for d


11. for 20. for g


12. for r 22. for d

Brain Busters Solve each equation for the indicated variable. (Leave in your answers.)

23. for R 24. for S


24. for r 26. for t


25. for I 28. for I

Solve each problem. When appropriate, round answers to the nearest tenth. See Example 3.

LI^2 +RI+ P=EI-RI^2

1

c

= 0

S=yt+

1

2

10 p^2 c^2 + 7 pcr= 12 r^2 gt^2

p= 1 E 702 S 16 S-t 2 =t^2

E^2 R

1 r+R 22



S= 4 pr^2 s=kwd^2

p=

B

k/

g

p= /

B

k/

g

F=

k

2 d

S= 2 prh+pr^2 D= 2 kh

V= V=p 1 r^2 +R^22 h At^2 +Bt=-C

1

3

pr^2 h

L=

kd^4

h^2

F=

kA

v^2

R=

k

d^2

I=

ks

d^2

d=kt^2 S= 6 e^2



1 m 702

gw^2 =kw+ 24

gw^2 = 2 r

9.4 EXERCISES

m

n

p

90 °

90 °

m

n p

29.Find the lengths of the sides of the

triangle.

30.Find the lengths of the sides of the

triangle.

x + 4

x + 1

x

2 m + 3

5 m

2 m