tìm x thỏa mãn 1 1/3 cộng 1 1/5 x x – 4,5 = 2 4/5

Đáp án:

`1 1/3 + 1 1/5 × x – 4,5 = 2 4/5` 

`4/3 + 6/5 × x – 9/2 = 14/5` 

`6/5 × x – 9/2 = 14/5 – 4/3` 

`6/5 × x – 9/2 = 22/15` 

`6/5 × x = 22/15 + 9/2` 

`6/5 × x = 179/30` 

`x = 179/30 : 6/5` 

`x = 179/36`

Vậy `x = 179/36`