So sánh:
E=\(\frac{1995^3+1}{1995^2-1994}\)và F=\(\frac{1996^3-1}{^{1996^2}+1997}\)
Giúp mk nha
# Thầy Soobin
Số nào lớn hơn trong hai số : \(E=\frac{1995^3}{1995^2-1994};F=\frac{1996^3-1}{1996^2+1997}\)
\(F=\frac{1996^3-1}{1996^2+1997}=\frac{\left(1996-1\right)\left(1996^2+1996+1\right)}{1996^2+1997}=\frac{1995.\left(1996^2+1997\right)}{1996^2+1997}=1995\)
E = \(\frac{1995^3}{1995^2-1994}=\frac{1995^3+1-1}{1995^2-1994}=\frac{\left(1995+1\right)\left(1995^2-1995+1\right)-1}{1995^2-1994}\)
=\(\frac{1996\left(1995^2-1994\right)-1}{1995^2-1994}=1996-\frac{1}{1995^2-1994}\)
Vì \(1995^2-1994>0\) => \(\frac{1}{1995^2-1994}-1\) => \(1996-\frac{1}{1995^2-1994}>1996-1\)
HAy E > F
Bài 1: a,37/53×23/48×535353/373737×242424/232323
b,1997×1996-995/1995×1997+1002
c,1995×1997-1/1996×1995+1994
/ là phần nhé giúp e câu này và ghi hết cách làm ra nha
a)37/53x23/48x535353/373737x242424/232323
=37/53x23/48x53/37x24/23
=851/2544x1272/851
=1/2
\(\frac{2}{7}\)+ \(\frac{5}{14}\)+\(\frac{1}{7}\)+\(\frac{3}{14}\)
\(\frac{1995×1997-1}{1996×1995+1994}\)
469 × 281 + 489 × 719
Giúp mình nha . Mai mình nội bài rồi :((
\(\frac{2}{7}\)+ \(\frac{5}{14}\)+\(\frac{1}{7}\)+ \(\frac{3}{14}\)=\(\frac{4}{14}\)+\(\frac{5}{14}\)+\(\frac{2}{14}\)+\(\frac{3}{14}\)=\(\frac{14}{14}\)=1
469x281+489x719=469x281+(469+20)x719=469x281+469x719+20x719=469x(281+719)+1438=469x1000+1438=469000+1438=470438
a\(\frac{2}{5}\)+\(\frac{5}{14}\)+\(\frac{1}{7}\)+\(\frac{3}{14}\)=\(\frac{53}{70}\)+\(\frac{1}{7}\)=\(\frac{9}{10}\)+\(\frac{3}{14}\)=\(\frac{39}{35}\)
b\(\frac{1995.1997-1}{1996.1995+1994}\)=3984008001
c 469x281+489x719
=(489-469)x(281+719)
=20x1000
=20000
1995 x 1997 - 1
------------------------------
1996 x 1995 + 1994
giúp em với ạ
\(\dfrac{1995x1997-1}{1996x1995+1994}=\dfrac{1995x\left(1996+1\right)-1}{1996x1995+1994}\)
\(=\dfrac{1995x1996+1995-1}{1996x1995+1994}=\dfrac{1995x1996+1994}{1996x1995+1994}=1\)
\(\frac{1}{2}\times\frac{1}{3}\times\frac{1}{4}\times...\times\frac{1995}{1996}\times\frac{1996}{1997}\)
1995^3+1/1995^2-1994
1996^2-1/1996^3+199
Tính diện tích miếng bìa màu xanh như hình bên 20cm 25cm
1995*1997-1/1996*1995+1994
\(\frac{1995.1997-1}{1996.1995+1994}\)
\(=\frac{1995.1996+1995-1}{1996.1995+1994}\)
\(=\frac{1995.1996+1994}{1996.1995+1994}=1\)
#
-\(\frac{1995\cdot1997-1}{1995\cdot1996+1994}\)
=\(\frac{1995\cdot\left(1996+1\right)-1}{1995\cdot1996+1994}\)
=\(\frac{1995\cdot1996+1995\cdot1-1}{1995\cdot1996+1994}\)
=\(\frac{1995\cdot1996+1994}{1995\cdot1996+1994}\)
=1
M= 1-2-3+4+5-6-7+8+...........+1993-1994-1995+1996+1997.
Tinh nhanh: M=1-2-3+4+5-6-7+8+...+1993-1994-1995+1996+1997