151 - 291 : 288 + 12 . 3
= 151 - 291-88 + 12 . 3
= 151 - 23 + 12 . 3
= 151 - 8 + 1 . 3
= 151 - 8 + 3
= 146
151 - 291 : 288 +12 .3
= 151 - 23 + 3
= 151 - 8 + 3
= 143 +3
= 146
thuc hien phep tinh
a. 2 nhan 7 mu 2 - 16 nhan 2 mu 3
b. 17 nhan 120 + 17 nhan ( -20 )
1 Thuc hien phep tinh
a 5 mu 16 : 5 mu 14 + 2 x 2 mu 3 - 101 mu 0
b 5 X + X = 39 - 45 : 5
bai 4 , tinh gia tri bieu thuc ;
a,A=2 mu 1 + 2 mu 2 +2 mu 3 +......+2 mu 2019
b, B=1+3+3 mu 2 +3 mu 3 +......+3 mu 2020
Tinh nhanh cac gia tri cua bieu thuc
[ ( 2 mu 5:2-2 mu 2×2 mu 2)×9999]+10000
Viet Ket qua phep tinh duoi dang mot luy thua :
a) 23 .22.2.4
B) 10 mu 2 .10 mu 3 .10 mu 5
C) X.X mu 5
D) A mu 3 .a mu 2 .a mu 5
B1) Tinh
a) 245-4 . [15: 8 +2.(4+3 mu 2 -9)]
b) 375: 5 mu 3 -( 3 mu 8: 3 mu 6 -2 .2 mu 3)
B2: Tim x
a) 2x -2 mu 3 .3 mu 2=138
b) ( 6x- 3 mu 4) . 7 mu 3= 3 . 7 mu 4
c) 1+2+3+..............+x =500500
bai 1; so sanh
a, 3 mu 600 va 2 mu 900 b, 2 mu 360 va 3 mu 240
c, 3 mu 236 va 2 mu 354
bai 2,tim x biet ;
a,5 mu x + 5 mu x +2 =650
b, 2 mu x +3 +5 nhan 2 mu x +2 - 2 mu x + 1 = 208
bai 3,tinh tong;A=3 + 3 mu 2 + 3 mu 3 +3 mu 4 +.........+3 mu 2019 +3 mu 2020
B=1/3+1/3 mu 3 +1/3 mu 5 +1/3 mu 7 + ...+1/3 mu 99
M= 3/1 mu 2 . 2 mu 2 +5/2 mu 2 . 3 mu 2+7/3 mu 2 . 4 mu 2 + ...+19= 9 mu 2 . 10 mu 2
