Tính nhanh:
a. - 55 . 75 + 13 (-75) . (-32)
b. 35. (65 - 24) - 65 (24 + 35)
2/15-2/65-4/39
32/13-(7/23+8/23)
(1/3+12/67+13/41) - (79/67 - 28/41)
38/45 - (8/45-17/51-3/11)
9/10 - 13/75 - 1/6
2/15 - 2/65 - 4/39
31/23 - (7/32 + 8/23)
(1/3+12/67+13/41) - (79/67 - 28/41)
38/45 - (8/45 - 17/51- 3/11)
1, Tính nhanh nếu có thể:
a) -87 + ( -750 ) + 2018- 13 + 750
b) ( 45 + 12 - 13 ) - ( 45 - 13 + 12 )
c) -15 . 56 + 43 . ( -15 )
d) -62 . 32 - 65 . 47 - 21 . 65
e) 24 . ( 16 - 5 ) - 16 . ( 24 - 5 )
g) 5 - 10 + 15 - 20 + ... + 2015 - 2020
1. thực hiện phép tính :
a/ 27 . 332 + 93 . 43 + 57 . 61 + 69 . 57
b/ 34 . 75 + 75 . 66 - 65 . 100
c/ ( 456 . 11 + 912 ) . 37 : 13 : 74
d/ 62 : 4 . 3 + 2 . 52
e / 5 . 42 - 18 : 32
g/ [ ( 315 + 372 ) . 3 + ( 372 + 315 ) . 7 ] : ( 26 . 13 + 74 .14 )
h/ 12 : { 390 : [ 500 - ( 125 + 35 . 7 ) ] }
k / 192000 - ( 1500 . 2 + 1800 . 3 + 1800 .2 : 3 )
1
a)34×35+35×86+65×75+65×45
b)652+327+148+15+73
c)341×67+341×16+659×83
d)13+15+17+...+199
2
a)32×(x-10)=64
b)461-(x-45)=387
c)(2×x+15)+342=1517
Tìm x :
a) 13 - 2 ( x + 1 ) = 7
b) 6x + 2 . 4 = 5^2 . 2
c) 420 + 65 . 4 = ( x + 175 ) : 5 + 30
d) 32 . 12 : 2 = ( x + 70 ) : 14 - 40
e) 231 - ( x - 6 ) = 1339 : 13
f) 10 + 2x = 4^5 : 4
g) 70 - 5 ( x - 3 ) = 45
BT1 : Tính nhanh nếu có thể :
a) -25 + 8 + 12 + 25
b) -87 + ( -750 ) + 2018 - 13 + 750
c) ( 45 + 12 - 13 ) - ( 45 - 13 + 12 )
d) -15 x 56 + 43 x ( -15 ) - 15
e) -62 x 32 - 65 x 47 - 21 x 65
g) 24 x ( 16 - 5) - 16 x ( 24 - 5 )
h) 5 - 10 + 15 - 20 + ............+ 2015 - 2020
BT3 : Tìm n thuộc Z biết :
a) 3n + 2 chia hết n - 1
b) n mũ 2 + 5 chia hết n+1
c) n + 1 chia hết n mũ 2 - 2
125-(-75)+32-(48+32)
47.347+247.(-47)
40.(45-135)-40.(45+65)
x-10=-14
15+x =13
25.x =-75
5x-16=-46
3.x-(-11)=-4
jup mik nhoa :(( mik ngao toan lam :((