Đặt \(A=1.2.3.4+2.3.4.5+...+97.98.99.100\)
\(5A=1.2.3.4.5+2.3.4.5.5+...+97.98.99.100.5\)
\(5A=1.2.3.4.5+2.3.4.5.\left(6-1\right)+...+97.98.99.100.\left(101-96\right)\)
\(5A=1.2.3.4.5+2.3.4.5.6-1.2.3.4.5+...+97.98.99.100.101-96.97.98.99.100\)
\(5A=97.98.99.100.101\)
\(A=\frac{97.98.99.100.101}{5}=1901009880\)
Tinh S=1/1.2.3.4+1/2.3.4.5+1/3.4.5.6+...+1/97.98.99.100
tinh gia tri cua bieu thuc sau mot cach nhanh
1992.1991 1991-1991.1992 1992
CHO bieu thuc
B=17,58*43+57*17,58/293*A
a)tim gia tri cua bieu thuc Bkhi a=2
b)tinh gia tri a khi B=2
c)tim gia tri so tu nhien ad biet bieu thuc B co gia tri lon nhat ,gia tri lon do la bao nhieu
tinh gia tri cua cac bieu thuc sau roi so sanh cac ket qua tinh duoc
(-25)-(-12), 18+(14-42), (-18)-13+17
tinh gia tri cua bieu thuc -90-(y+10)+100 voi p=-24
tinh gia tri cua bieu thuc A=1.2+2.3+3.4+...2005.2006
tinh gia tri cua bieu thuc
136.(-47)+36.47
tinh gia tri cua bieu thuc 9/40-11/60+13/84-15/112
Tinh gia tri cua bieu thuc:
2002.20012001-2001.20022002
