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
5 = c. infinite.
6 = I don't know. sorry!!
Hope this helps!!
Answer:
h(t) = -5t + 500
Step-by-step explanation:
At time zero, the elevator is at 500 ft.
At time 5 seconds, the elevator is at 475 ft.
The difference in height is -25 ft.
The elevator traveled -25 ft (25 ft down) in 5 seconds, so it travels at a speed of 5 ft per second. Since it is traveling down, its speed is -5 ft/sec.
For each second of travel, it loses 5 ft of height.
h(t) = -5t + 500
Answer:
80/140 = (80:20)/(140:20) = 4/7
4/7 = (4*4)/(7*4) = 16/28
4/7 = (4*5)/(7*5) = 20/35 not 20/28 not 20/32
4/7 = (4*5.5)/(7*5.5) = 22/38.5 not 22/37
