The cost C of manufacturing a model is partly constant and partly as h where h be the height of the model. When h = 4, C = 21; when h = 6, C = 59.
a)Find the equation connecting the cost C and the height h
b)Find the cost when h = 7
c)Find h when C = 7
y varies jointly as w2 and u. If y=24 when w=2 and u=3,
(a)Write an equation connecting y, w and u
(b)Find y as w=3 and u=5
幫幫手...唔識做
2006-12-18 3:51 am
回答 (1)
2006-12-18 4:41 am
✔ 最佳答案
a)let C=M+kh
When h = 4, C = 21; when h = 6, C = 59.
21=M+4k
59=M+6k
so 2k=38, k=19
21=M+4(19)
M=-55
C=-55+19h
b)
when h = 7
C=-55+19*7=78
c)
when C = 7
7=-55+19h
h=3.2632
2
(a)
let y=Muw^2 .
24=M*3*2^2
M=2
so
y=2uw^2
b)
when w=3 and u=5
y=2*5*3^2=90
收錄日期: 2021-04-25 16:54:51
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