How do I subtract one fraction from another?

If you have the question:

What is 2/3 minus 1/5?

You should start this question by looking at the demoniators (the bottom of the fraction). You want to get a number that is divisible by both 3 and 5. An example is 15 as it can be divide by both 3 and 5:

15/3=5

and

15/5=3

Now that we have picked our denominator, you need to change the number on top, the numerator. To do this, take the original denominator (3) and divide it by our new one

15/3=5

We now know that the numerator is out by a factor of 5. To make the fraction equivelant, you need to times the top number (2) by the factor (5).

2*5=10

Do the same with the second number and you should get the answer 3.

Now we have 10/15 minus 3/15=(10-3)/15=7/15 and we have our answer!

JC

Related Maths GCSE answers

All answers ▸

Factorise: x^2+2x-3


Billy wants to buy these tickets for a show. 4 adult tickets at £15 each 2 child tickets at £10 each A 10% booking fee is added to the ticket price. 3% is then added for paying by credit card. Work out the total charge when paying by credit card.


Solve the simultaneous equations. 5x+y=21, x-3y=9.


Solve x2 +2x – 4 = 0, leaving your answer in simplest surd form (4 marks, non calculator question)