Tinh gia tri bieu thuc:
[109/6-(0,06:15/2+17/5.0,38]:(16-8/3.19/4)
[109/6-(0,06:15/2+17/5.0,38]:(16-8/3.19/4)
Tinh gia tri bieu thuc
2-4-6+8+10-12-14+16+.......-2006+2008+2010-2012
tinh nhanh gia tri cac bieu thuc sau
a , 1/ 2+ 1 /3 + 1 / 4 + 1/ 6
b, 53 / 4 . 11/ 16 - 23/4 . 11/16
c, 3/ 8 . ( 2 /9 + 4 /15 )
a , 1/ 2+ 1 /3 + 1 / 4 + 1/ 6
=5/6+1/4+1/6
=1+1/4
=5/4
b, 53 / 4 . 11/ 16 - 23/4 . 11/16
=11/16(53/4+23/4)
=11/6.19
=209/6
53 / 4 . 11/ 16 - 23/4 . 11/16
=11/6,19
=209/6
Tinh gia tri cua bieu thuc :
3/4 nhan 8/9 nhan 15/16 nhan ...nhan 99/100 =
ko được phép đăng ak
tinh gia tri bieu thuc 1+2+3...+16+17+18
tinh gia tri cua bieu thuc: B=1*2*3+2*3*4+3*4*5+4*5*6+.....+17*18*19
tinh gia tri cua bieu thuc sau: S=2^1+2^2+...+2^15-2^16
tinh gia tri bieu thuc :
3/4 x 8/9 x15/16 x.....x99/100
tinh gia tri bieu thuc: B=1*2*3+2*3*4+3*4*5+...+17*18*19
B = 1.2.3 + 2.3.4 + 3.4.5 + .... + 17.18.19
<=> 4B = 1.2.3.4 + 2.3.4.4 + 3.4.5.4 + .... + 17.18.19.4
<=> 4B = 1.2.3.(4 - 0) + 2.3.4.(5 - 1) + 3.4.5.(6 - 2) + .... + 17.18.19.(20 - 16)
<=> 4B = 1.2.3.4 + 2.3.4.5 - 1.2.3.4 + .... + 17.18.19.20 - 16.17.18.19
<=> 4B = 17.18.19.20 = 116280
<=> B = 116280 : 4 = 29070
B = 1.2.3 + 2.3.4 + 3.4.5 + .... + 17.18.19
<=> 4B = 1.2.3.4 + 2.3.4.4 + 3.4.5.4 + .... + 17.18.19.4
<=> 4B = 1.2.3.(4 - 0) + 2.3.4.(5 - 1) + 3.4.5.(6 - 2) + .... + 17.18.19.(20 - 16)
<=> 4B = 1.2.3.4 + 2.3.4.5 - 1.2.3.4 + .... + 17.18.19.20 - 16.17.18.19
<=> 4B = 17.18.19.20 = 116280
<=> B = 116280 : 4 = 29070