bai 1; cho tong M =126 +213+x. Tim x de M chia het cho 3
bai 2; chung to rang tong ; A= 2 + 2 mu 3 + 2 mu 4 + 2 mu 5 + 2 mu 6 +2 mu 7 +2 mu 9 + 2 mu 10 + 2 mu 12 chia het cho 5
a, (1/2)mu x =64
b, x mu 3 +27 =0
c, 3 mu 2 /2 mu n =4
d, 625 / 5 mu n = 5
e, 27 mu n . 3 mu n = 3 mu 2
so sanh
a, 3 mu 200 va 2 mu 300
b, 2 mu 225 va 3 mu 150
bai 1;tim x biet ; a, 2 . (x-3)=5mu2-7 b, 23-2 mu 2 . ( x+4)=3 mu 3 -6 c, x . 2 mu 4 -3 mu 2 =7 mu 2 -(5 mu 2 -13)
bai 2 ; tinh hop li ;
a, 43.75 +43.25 b, 14.73+2.7 .37 -28.5 c, 34.56+44.17 .2+100.66
bai 5 ;tinh a,{92-[(4 mu 2 +71.2mu2);15]}-13
b, 360;{300;[150-5 mu 2 . (10 -2 mu3 )]}
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
1) tim x thuoc n biet:
a) 3 mu 4 - x = 81
b) 5 mu x -1 = 125
c) (2 - x) mu 3=27 mu 0
d)3 mu x + 2 -3 mu x +1=182
e) 2 mu x -1 -2 mu x =16
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
1.tim x thuoc n biet:
a)3 mu x .3 b)x mu 20 = x c)2 mu x.16 mu 2=1024 d)64.4 mu x=16 mu 8
2.tim n thuoc n sao:
a)3 mu 2.3 mu n=3 mu 5 b)(2 mu 2:4).2mu n=4 c)32<2 mu n<128 d)2.16>_2 mu n>4
ai giai dung va nhanh minh tick cho
So sanh :
a, 9 mu 5 va 27 mu 3
b, 3 mu 200 va 2 mu 300
c, 31 mu 11 va 17 mu 14
d, 199 mu 20 va 2003 mu 15
e, 2 mu 1993 va 7 mu 714
bai 3 tim x , biet;
a, 3 mu x =81 b, 2 mu x-3=16 c, 5 mu 2x-3=25 d, [x-1]mu 5=32 e, [2x+3]mu 2 =49 f, 2[5-x]mu 2=49