a)( 124 x 237 + 152 ) : ( 870 + 235 x 122 )
= 29540 + 29540
= 29540 x 2
= 59080
b) 101 + 100 + 99 + 98 + ... + 3 + 2 + 1
= ( 101 - 1 ) : 1 + 1] x ( 101 + 1 ) : 2
= 101 x 102 : 2
= 10302 : 2
= 5151
c) 101 - 100 + 99 - 98 + .. 3 - 2 + 1
(101-100) + (99-98) + ... + (5-4) + (3-2) +1
=1 + 1 + ... + 1 + 1 + 1
= 1 x 51
= 51
A=101+100+99+98+...+3+2+1/101-100+99-98+...+3-2+1
B=3737.43/4343.37
101+100+99+98+...+3+2+1/101-100+99-98+...+3-2+1
tính
A=101+100+99+99+98+.........+3+2+1
---------------------------------------------------------------
101- _100+99-98+.....+3-2+1
\(\frac{101+100+99+98+.....+5+4+3+2+1}{101-100+99-98+...+5-4+3-2+1}\)
100 + 99/2 + 98/3 + .......... 2/99 + 1/100 : 100/2 + 100/3 +.......+ 100/100+100/101
\(\frac{101+100+99+...+3+2+1}{101-100+99-98+...+3-2+1}\)
Tính nhanh
Tính bằng cách hợp lí ( 124 x 237 + 152 ) : ( 870 + 235 x 122 )
A=1+2+3+4+5+6...95+96+97+98+99+100+101 = ?
1+2-3-4+5+6-7-8+...+97+98-99-100+101
