Question

Giselle works as a carpenter and as a blacksmith.

Answer 1

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