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
Answer:
2.4 or 2 2/5
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
If 12 pencils are 1.25, 24 would be 2 x 1.25. And 4 notebooks worth 0.65 would be 4 x 0.65
Added up, this expression is:
(2 x 1.25) + (4 x 0.64)
Well if 49 is the area, and you get area by multiplying one side by another side, and its a square so the numbers are going to be the same, so you would be multiplying two of the same numbers. And two of the same numbers that equal 49 is 7.
