We first need to add the two parts of the ratio to find the total number of parts:
3 + 4 = 7 parts
We then need to divide the £56 by the total number of parts:
56/7 = 8
We can then work out the new ratio by multiplying both sides by 8:
3*8:4*8
This gives an answer of:
£24:£32
(You check this is correct by adding the two sides and seeing if they add up to £56)
