中二數學..吾識..THZ

A = a(1 - R)/R
= (4)(1 - 0.5)/0.5
= (4)(0.5)/0.5
= 4
answer is C
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y = a + kx
27 = 12 + 3x
3x = 15
x = 5
answer is B
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V = pi r^2 h / 3
616 = (22/7) (7^2) h / 3
616 = (22) (7) h / 3
(22) (7) h = 1848
h = 12
answer is C

Answers
4C
5B
6C

2011-01-03 20:45:49 補充：
4. A=a(1-R)/R
If a=4, R=0.5, Then
A = 4(1-0.5) / 0.5
A=4
Answer C
5. y = a+kx
If y=27, a=12, k=3, Then
27 = 12 + 3x
15 = 3x
x = 5
Answer B
6. By V=1/3 pi sq.r h
616=1/3 x 22/7 x 7x7 x h
h = 12
Answer C