我想問下列幾條數點做呀? 教教我

1. Solve the inquality x/3+(x-1)/2 > 1.
x/3+(x-1)/2 > 1
2x + 3(x-1) > 6
5x - 3 > 6
5x > 9
x > 9/5
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2. (a) Give that a:b = 2:3 and b:c = 1:2. Find a:b:c.
a:b = 2:3
b:c = 1:2 = 3 : 6
a:b:c = 2 : 3 : 6
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(b) Convert 8610 to binary.
8610
= (1)(2^6) + (0)(2^5) + (1)(2^4) + (0)(2^3) + (1)(2^2) + (1)(2^1) + (0)(2^0)
= 1010110 (2)
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3. It shows a hemisphere with radius r cm. The total surface area of hemisphere is A cm².
(a) Express A in terms of r.
A = π r^2 + 2 π r^2 = 3 π r^2
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(b) Change r as the subject of the fornula in part (a).
r^2 = A/(3 π)
r = sqrt( A/(3 π) )
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(c) If total surface area of the hemisphere is 48π cm², find the radius of the hemisphere
r = sqrt( 48π/(3 π) ) = sqrt(16) = 4 cm