Two fifths of a pile of coal was used in the first time, and three eighths of it was used in the second time. There are 180 kg left. How many kg of this pile of coal Using the equation solution,

Two fifths of a pile of coal was used in the first time, and three eighths of it was used in the second time. There are 180 kg left. How many kg of this pile of coal Using the equation solution,

Suppose this pile of coal is x kg
x-2/5x-3/8x=180
(1-2/5-3/8)x=180
9/40x=180
x=180*40/9
x=800
A: this pile of coal is 800 kg

One third of the number a is equal to two fifths of that of art. The number a is 2.4 larger than the number B. the number a is (), and the number B is (0
Such as the title

1 / 3A = 2 / 5B
A-B = 2.4 ②
A = 14.4
B = 12

The number of a is 80 more than that of B. one third of a is equal to two fifths of B. the number of a is ()

Let the number a be x and the number B be y
X-Y=80
(1/3)X=(2/5)Y
We can see that y = x-80, substituting (1 / 3) x = (2 / 5) y, there is
5x = 6y, that is, 5x = 6 (x-80),
There are 5x = 6x-480,
We get x = 480, y = 400