Respuesta :
Step-by-step explanation:
let x is total hours of carpenter and y is total hours of blacksmith
total hours --
x + y = 30 - equation 1
total earnings -
20x +25y = 690 - equation 2
from equation 1 ,
x = 30 - y
20(30-y) +25y =690
600 - 20y +25y =690
5y =90
y=18
x=30-18 =12
carpenter= 12 blacksmith=18
Answer:
Giselle worked as a carpenter for 12 hours and as a blacksmith for 18 hours last week.
Step-by-step explanation: