Question

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Answer 1

'transform' all divisions to the same number under the line. Try to find the smallest common denominator, which is '20' here. 3/5 equals 12/12, for example. Once all of these divisions have the same denominator, you can easily add the top part and calculate the sum.

Answer 2

Sorry, not 12/12, but 12/20...you'll get it anyway.

Answer 3

Try taking LCM!
The lowest common multiply here is 20 right?
Because it is divisible by ALL OTHER DENOMINATORs! :)
SO
\[\frac{ 3 }{ 5 } + \frac{ 1 }{ 10 } - \frac{ 9 }{ 20 }\]
So after taking LCM we get!
\[\frac{ 3X4 }{ 5X4 } + \frac{ 1X2 }{ 10X2 } - \frac{ 9X1 }{ 20X1 }\]
Now just simply add and subtract them!
\[\frac{ 3X4 + 1X2 - 9 }{ 20 }\]
\[\frac{ 5 }{ 20 } = \frac{ 1 }{ 4 }\]
Get this? :)

Answer 4

:)