a)tach abc thanh abc+8
b)abc x 9=3abc
=>abc x 9=3000+abc
=>abc x9 -abc =3000
=>abc x (9-1)=3000
=>abx x8=3000
=>abc=3000:8
=>abc=375
a. abc + 1133 = abc8
=> abc + 1133 = 10 x abc + 8
=> 1133 - 8 = 10 x abc - abc
=> 1125 = 9 x abc
=> abc = 1125 : 9
Vậy abc = 125.
b. abc x 9 = 3abc
=> abc x 9 = 3000 + abc
=> abc x 9 - abc = 3000
=> abc x 8 = 3000
=> abc = 3000 : 8
Vậy abc = 375.
a,
abc + 1133 = abc8 hay
abc + 1133 = abc x 10 + 8
1133 = abc x 9 + 8
abc x 9 = 1133 – 8 =1125
abc = 1125 : 9
abc = 125
b,
abc x 9 =3abc => abc x 8 + abc = 3000 + abc
abc x 8 = 3000 => abc = 3000 : 8
abc = 375
