If 750 g of meat costs £9.60 how much does 1 kg of meat cost

After a while you will be able to do these almost 'in your head'....in the meantime, let's set this up as a ratio

.75kg/9.60 = 1kg/x     where 'x' is the price you are looking for

x=1kg x L9.60/.75kg     the kg 'cancels' and you are left with = L 12.80