32-(5-8+32)+(5-8+6)
Cách 1:
= 32 - 5 + 8 - 32 + 5 - 8 + 6
= 27 + 8 - 32 + 5 - 8 + 6
= 35 - 32 + 5 - 8 + 6
= 3 + 5 - 8 + 6
= 8 - 8 + 6
= 0 + 6 = 6
Cách 2:
32-(5-8+32)+(5-8+6)
= 32 - 5 + 8 - 32 + 5 - 8 + 6
= ( 32 - 32) + ( 5 - 5) + ( 8- 8) + 6
= 0 + 0 + 0 + 6 = 6
giup em voi em hoc toan nang cao lop 5 ma lai co bai lop 6 la : x . 2^32 = 8^11 ; 2^x+1 : 8 = 32^5
1. x - 8 +32= 68
2. x +8+32=68
3. 98-x +34=43
4. 98+x-34=43
5. x :5:4=800
6. 18+x=384:8
7. (84,6-2 x x):3,02= 5,1
8. x x5= 120:6
9. (15x 24-x) :0,25= 100:0,25
S = 6 /2×5+6/5×8+6/8×11+...+6/29+32-1/n-1n+1=n×(n+1)
1) 15 - 98 + 91 - 75 + 98 - 91 - 13
2) 5 - ( 4 - 7 + 12 ) + ( 4 - 7 + 12 ) - 10
3) 20 - ( 25 - 98 + 12 ) + ( 25 - 98 - 72 )
4) - ( 17 - 4 + 13 + | -17 | + 13 )
5) | -16 | - ( 5 - 8 + 7) - ( - 5 ) - 8
6) -20 + ( 3 - 16 + 7 ) - ( 3 - 16 + 7 )
7) 32 - ( 5 - 8 + 32 ) + ( 5 - 8 + 6 )
8) -20 - ( 25 - 11 + 8 ) + ( 25 - 8 + 20 )
1. Tính nhanh
a) A=1/ 5 .6 + 1/ 6 .7 + 1/ 7. 8+ ... + 1/24 . 25
b) B= 2/ 3 .5 + 11/ 8 .19 + 13/ 19 .32 + 25/ 32 . 57 + 30/ 57 . 87
a. -7 – 9 =
b. -15 – 8 =
c. -28 – 32 =
d. -43 – 32 =
e. – 5 – 9 – 11 =
f. – 6 – 8 – 13 =
g. – 3 – 7 – 25 =
h. – 7 – 4 – 15 =
(/ là phần, * là cộng)
Tính nhanh:
A= 1/2 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 + 1/72
B= 1/5*6 + 1/6*7 + 1/7*8 +........+ 1/24*25
C= 2/3*5 + 3/5*8 + 11/8*19 + 13/19*32 + 25/32*57 + 30/57*87
Tìm x, biết :
3/2 + 5/4 + 9/8 + 17/16 + 33/32 - 6 + x-1/x+1 = 31/32 - 2/2015
