How to do this question plz

adult = £7 and child = £2

Step-by-step explanation:

let a represent adult ticket and c child ticket, then

2a + 3c = 20 → (1)

a + 4c = 15 → (2)

Multiply (2) by - 2 and add to (1) to eliminate a

- 2a - 8c = - 30 → (3)

Add (1) and (3) term by term

- 5c = - 10 ( divide both sides by - 5 )

c = 2

Substitute c = 2 into either of the 2 equations and solve for a

Substituting into (1)

2a + 3(2) = 20

2a + 6 = 20 ( subtract 6 from both sides )

2a = 14 ( divide both sides by 2 )

a = 7

Cost of adult ticket is £7 and child ticket is £2

i think the answer is seven, for if i'm being useless °ω°

step-by-step explanation: