Toán Lớp 5: Tìm x+2/5=1/2 ; x-2/5=2/7 ;x.3/4=9/20 ; x:1/7=14

Question

Toán Lớp 5:  Tìm x+2/5=1/2 ; x-2/5=2/7 ;x.3/4=9/20 ; x:1/7=14

minhtamnguyet88 · Answer

x + 2/5 = 1/2               x = 1/2 - 2/5               x = 5/10 - 4/10               x = 1/10     Vậy x = 1/10     x - 2/5 = 2/7              x = 2/7 + 2/5              x = 10/35 + 14/35              x = 24/35     Vậy x = 24/35     x . 3/4 = 9/20              x = 9/20 : 3/4              x = 9/20 . 4/3              x = 3/5     Vậy x = 3/5     x : 1/7 = 14              x = 14 . 1/7                x = 2     Vậy x = 2

hiennhi98 · Answer

x+2/5=1/2   x=1/2-2/5   x=5/(10)-4/(10)   x=1/(10)   Vậy x=1/(10)   _____________________________   x-2/5=2/7   x=2/7+2/5   x=(10)/(35)+(14)/(35)   x=(24)/(35)   Vậy x=(24)/(35)   ____________________________   x.(3)/4=9/(20)   x=9/(20):3/4   x=9/(20).(4)/(3)   x=3/5   Vậy x=3/5   ____________________________   x:1/7=14   x=14.(1)/7   x=2   Vậy x=2