Answer: the value of 7x-y is -14.
Step-by-step explanation:
When x=2 and y=4,
To find the value of 7x - y when x =2, y = 4, this means when ever you see x, put 2 in replacement, y, put 4 respectively.
7x - y = 7(2 - 4)
14 - 28
= -14.
Answer:
I inserted an image of the equation.
Step-by-step explanation:
Hope this helps!
Answer:
The tank will empty in 4 hours.
Step-by-step explanation:
Since a barrel contains 56 liters of kerosene, and it has two taps, one tap that draws 500 ml every 6 minutes and after first 5 liters are drawn from the barrel, the second tap also starts, and it draws 1 liter in every 5 minutes, to determine how many hours will be taken in all to empty the tank, the following calculation must be performed:
0.5 x X = 5
X = 5 / 0.5
X = 10
10 x 6 = 60
1 hour = 51 liters
1 hour 30 minutes = 51 - (1 x 6) - (0.5 x 5) = 42.5
2 hours = 42.5 - (1 x 6) - (0.5 x 5) = 34
2 hours 30 minutes = 34 - (1 x 6) - (0.5 x 5) = 25.5
3 hours = 25.5 - (1 x 6) - (0.5 x 5) = 17
3 hours 30 minutes = 17 - (1 x 6) - (0.5 x 5) = 8.5
4 hours = 8.5 - (1 x 6) - (0.5 x 5) = 0
Therefore, the tank will empty in 4 hours.
