7/10 - y x 3/4 = 1/5
7/10 - y = 1/5 : 3/4
7/10 - y = 4/15
y = 7/10 - 4/15
y = 13/30
7/10 - y x 3/4 =1/5
=>y=1/5 :3/4
=>y =4/15
=>y =7/10 - 4/15
=>y =13/30
Mình bị nhầm đẻ mình giải lại cho:
7/10 - y x 3/4 = 1/5
y x 3/4 = 7/10 - 1/5
y x 3/4 = 1/2
y = 1/2 : 3/4
y = 2/3