Given that y varies jointly as x and z, and y = 13 when x = 5 andz=8, find the following:
a. y when x= 4 and z=10
b. x when y= 20 and z = 12
c. z when x=6 and y=15

Step-by-step explanation:

y=kxz

13=k x 5 x 8

13= 40k

K=13/40

a. y=13/40 x 4 x 10

y=13/40 x 40

y=13

b. 20=13/40 x x x 12

20=13/40 x 12x

20=156x

40

20 x 40=156x

800=156x

X=800

156

X=200

39

X=5 5/39

C. 15=13/40 x 6 x z

15=78z

40

15x40=78z

600=78z

Z=600

78

Z=100

3

Z=7 9/13

answer:

125 yards

explanation:

75+50=125. that is my answer