If you are trying to figure out x-9=15 it’ll be 24
The two labeled angles are alternate exterior angles, and as such, they are equal. This means that we can set up and solve the following equation:

Answer:
x = (66.50 - 4y) / 3
Step-by-step explanation:
Given that:
Amount had = $70
Change collected = $3.50
Total amount spent = $(70 - 3.50) = $66.50
Total amount used for purchasing prawn and fish:
Kg of fish = 4
Kg of prawn = 3
1 kg prawn will cost, x
If 1 kg of fish = y
(Total amount spent - cost of 4 kg fish) / Number of kg of prawn
($66.50 - 4y) / 3
x = (66.50 - 4y) / 3
A coefficient is a numerical or constant quantity placed before and multiplying the variable in an algebraic expression (e.g. 4 in 4x).
The 2 and + are out since they don't have variables(and the + is just a +).
So 4 and x are left. x is a variable, not a coefficient, so the last(and correct) answer is 4.
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hope it helps