She worked as a carpenter for 12 hours and as a blacksmith for 18 hours.
Assuming you mean she earned $20 as a carpenter and $25 as a blacksmith per hour, with a total of 30 hours for $690,
let c represent carpenter hours and b for blacksmith hours.
20c + 25b = 690
c + b = 30
Subtract b from each side so that c = 30 - b
Plug this value into the first equation
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
600 + 5b = 690
5b = 90
b = 18
To find c, plug this value of b into the other equation
c + 18 = 30
c = 12
Im pretty sure the answer would be A, B & D
7000 because if the hundred next to the thousand is below 5 the number will be the same
eg: 3200 the answer will be 3000
but if the number is 5 and higher the thousand will be one extra
eg 1: 3521 the answer will be 4000
eg 2: 4809 the answer will be 5000
Answer:
false?
Step-by-step explanation:
first, you put this question in mathematics. columbia is a “democracy” but i would say it isn’t peaceful.