Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
B=1-2-3+4+5-6-7+8+..........+21-22-23+24
B=(1-2-3+4)+(5-6-7+8)+.......+(21-22-23+24)
B=0+0+............+0
B=0
[ -1+2] + [ 3-4-5+6 ] + [ 7-8-7+10 ] + [ 11-12-13+14 ] + ................+ 99-100-101
= 1 + 0+0+0+0+...............+-102
= -101
\(A=\dfrac{5}{11}.\dfrac{5}{7}+\dfrac{5}{11}.\dfrac{2}{7}+\dfrac{6}{11}=\dfrac{5}{11}\left(\dfrac{5}{7}+\dfrac{2}{7}\right)+\dfrac{6}{11}=\dfrac{5}{11}.1+\dfrac{6}{11}=\dfrac{5}{11}+\dfrac{6}{11}=\dfrac{11}{11}=1\)
\(B=\dfrac{3}{13}.\dfrac{6}{11}+\dfrac{3}{13}.\dfrac{9}{11}-\dfrac{3}{13}.\dfrac{4}{11}=\dfrac{3}{13}\left(\dfrac{6}{11}+\dfrac{9}{11}-\dfrac{4}{11}\right)=\dfrac{3}{13}.1=\dfrac{3}{13}\)
\(C=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right)\left(\dfrac{3}{6}-\dfrac{2}{6}-\dfrac{1}{6}\right)=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right).0=0\)
B = ( 1024 . 10 . 15625 + 9765625 . 256 ) : ( 256 . 625+78125 . 32 )
=( 160000000+2500000000 ):( 160000+2500000)
= 2660000000 : 2660000
= 1000
B = ( 1.024 . 10 . 15.625 + 9.765.625 . 256 ) : ( 256 . 625+78125 . 32 )
B =( 160.000.000+2.500.000.000 ):( 160.000+2.500.000)
B = 2.660.000.000 : 2.660.000
B = 1.000
1+(-2)+3+(-4)+5+(-6)+...+21+(-22)=[1+(-2)]+[3+(-4)]+...+[21+(-22)]
-----------11 cặp----------------------
=(-1)+(-1)+...+(-1)=(-1).11=-11