Answer:
adult = £5
child = £2
Step-by-step explanation:
a = adult c = child
3a + 4c = 23
1a + 5c = 15
multiply second equation by 3 and rewrite
3a + 4c = 23
3a + 15c = 45
subtract
0 - 11c = - 22
-11c = -22
11c = 22
c = £2
subsitute into one of the equations and solve for a
1a + 5c = 15
a + 5(2) = 15
a + 10 = 15
a = £5