Step-by-step explanation:
$20/hr carpenter pay
$25/hr blacksmith pay
Let c = hours working carpentry
Let b = hours working as blacksmith
c + b = 30 {equation 1}
20c + 25b = 690 {equation 2}
In equation 1 solve for one variable in terms of the other.
c = 30-b
Substitute that into equation 2:
20(30-b) + 25b = 690
600 - 20b + 25b = 690
5b = 90
b = 90/5
b = 18 hours working as a blacksmith
c = 30-b = 30-18 = 12 hours as a carpenter
If you are given $10 every 3.5 hours and you want to find the unit rate per hour, you want to solve for how much money you make every hour. You do this by dividing the $10 by the 3.5 hours, which will result in about $2.86 per hour. (This is a rounded value)
Answer:

Step-by-step explanation:
We are required to solve for c in the equation: 
Step 1: Collect like terms

Step 2: Find the Lowest Common Multiple of the denominators
LCM of 8 and 5 is 40
Step 3: Multiply all through by 40

Step 4: Simplify
40c=32-5
40c=27
Step 5: Divide both sides by 40 and simplify if possible.

Answer:
x = -1
y = 9
Step-by-step explanation:
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