Maths dont no how to do?(Form 1)(English)

Let x kg be the weight of oil in the large bottle.
Then, (4 - x) kg is the weight of oil in the small bottle.

[ x - 1/4 x ] / [(4 - x) + 1/4 x ] = 3 / 2
[ 3/4 x ] / [4 - 3/4 x ] = 3 / 2
2 (3/4) x = 3 (4 - 3/4x) <--------------交叉相乘
3/2 x = 12 - 9/4 x
6x = 48 - 9x <-------------兩邊 x 4
15x = 48
x = 3.2

Therefore, weight of oil in large bottle is 3.2 kg
Weight of oil in small bottle = 4 - 3.2 kg = 0.8 kg

Given:
Total weight of oil : 4 kg
Let the oil in the large bottle is X kg
then: the oil in the small bottle is 4-X kg
When 1/4 of oil in large bottle is transfered to small, the oil remain in the large bottle is 3X/4; and after the transfer of the oil into the small bottle, the oil in the small bottle becomes X/4+4-X
The ratio of oil after transfer : 3:2
Setting up the equation:
3X/4 : (X/4 + 4 - X) = 3 : 2
solving the equation:
6X/4 = 3X/4 + 12 - 3X
15X = 48
X = 3.2 kg
The weight of oil in large bottle : 3.2 kg
The weight of oil in small bottle : 4 - 3.2 kg = 0.8 kg