Bài Làm:
1.
a) 2057 x 13 = 26741 | 428 x 125 = 53500 | b) 7368 : 24 = 307 | 13498 : 32 = 421 dư 26 |
2.
a) 40 x $x$ = 1400
$x$ = 1400 : 40
$x$ = 35
b) $x$ : 13 = 205
$x$ = 205 x 13
$x$ = 2665
3.
13 500 = 135 x 100
26 x 11 > 280
1600 : 10 < 1006
4.
a) a x b = b x a
(a x b) x c = a x (b x c)
a x 1 = 1 x a = a
a x (b + c) = a x b + a x c
a : 1 = a
a : a = 1 (a khác 0)
0 : a = 0 (a khác 0)
p x m + p x n = p x (m + n)
b) a x (b : c) = a x b : c
a : (b x c) = a : b : c
a : (b : c) = a : b x c