Answer:
Correct answer: First x = 15 h and second y = 5 h
Explanation:
To solve this problem we will form a system of two equations with two variables:
Let be the time of the first mechanic x and of the second y
x + y = 20 ⇒ y = 20 - x
85 x + 80 y = 1675
85 x + 80 (20 - x) = 1675
85 x + 1600 - 80 x = 1675
5 x = 1675 - 1600
5 x = 75
x = 75 / 5 = 15 h
x = 15 h
y = 20 - 15 = 5 h
y = 5 h
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