Answer:
14
Step-by-step explanation:
1/2x = 1/7x + 5
1/2x - 1/7x = 5
7/14x - 2/14x = 5
5/14x = 5
x = 5 * 14/5
x = 14
The first mechanic worked for 10 hours and the second mechanic worked for 15 hours.
Step-by-step explanation:
Given,
Charges of first mechanic = $95 per hour
Charges of second mechanic = $115 per hour
Total hours = 25
Total amount charged = $2675
Let,
The number of hours worked by first mechanic = x
The number of hours worked by second mechanic = y
According to given statement;
x+y=25 Eqn 1
95x+115y=2675 Eqn 2
Multiplying Eqn 1 by 95

Subtracting Eqn 3 from Eqn 2

Dividing both sides by 20

Putting y=15 in Eqn 1

The first mechanic worked for 10 hours and the second mechanic worked for 15 hours.
Keywords: linear equation, elimination method
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Answer:
5.96666666667
Step-by-step explanation:
I used a calculator
The answer is C) $30.00.
First, find out how much 1lb costs. 1lb would cost 1/4 of 4lb.
$10×1/4=$2.50/1lb.
So 12 pounds would be 12x the cost of 1lb.
$2.50×12 pounds=$30/12lb.