`1)`
`a) (x + 12,39) × 0,76 = 205,8`
`(x + 12,39) = 205,8 : 0,76`
`x + 12,39 = 270,7894...`
`x = 270,7894... - 12,39`
`x = 258,3994...`
`b) 325,02 - x = 8,37 × 13,8`
`325,02 - x = 115,506`
`x = 115,506 + 325,02`
`x = 440,526`
`c, 36 × x + 12,67 = 49,67`
`36 × x = 49,67 - 12,67`
`36 × x = 37`
`x = 37 : 36`
`x = 1,0277...`
`2)`
`a, 125 × 10,8 × 0,8 : 0,9`
`= (125 × 0,8) × 10,8 : 0,9`
`= 100 × 12`
`= 1200`
`b, 28,38 : 0,125 + 42,65 : 0,125 + 1 : 0,125`
`= 28,38 × 8 + 42,65 × 8 + 1 × 8`
`= (28,28 + 42,65 + 1) × 8`
`= 72,03 × 8`
`= 576,24`
Mình làm cho có, bạn nhớ cho bạn kia hay nhất nhé!