Answer:
55p
Step-by-step explanation:
iced cake = 10p more than a plain cake
iced cake = 10p + plain cake
iced cake and a plain cake together = £1
iced cake + plain cake = £1
if iced cake = 10p + plain cake, we can plug this into our second formula to get
(10p + plain cake) + plain cake = £1
10p + 2 * plain cake = £1 = 100p
subtract 10p from both sides to isolate the variable and its coefficient
2 * plain cake = 90p
divide both sides by 2 to isolate the variable
plain cake = 45p
iced cake = 10p + plain cake = 55p
