A= \(\dfrac{1993\left(1994+1\right)}{1995\left(1992+1\right)}\)=1

B=\(\dfrac{399\left(45+55\right)}{1995\left(1996-1991\right)}\)=\(\dfrac{399.5.100}{399.5.5}\)=100

đáp án là : 4

tên hay z

Tôi cần giải hộ chứ không cần tên hay

a, 2 x 3 x 4 x 8 x 50 x 25 x 125                                                         b, 45 x 128 - 90 x 64

= ( 2 x 50 ) x ( 4 x 25 ) x ( 8 x 125 ) x 3                                              = 45 x ( 128 - 2 x 64 )

= 100 x 100 x 1000 x 3                                                                       = 45 x 0

= 30000000                                                                                         = 0

c, 0,48 x 500 - 2,4 x 40 x 2         

= 0,48 x 100 x 5 - 2,4 x 10 x 4 x 2

= 48 x 5 - 24 x 8

= 24 x ( 2 x 5 - 8 )

= 24 x 2 

= 48

d, \(\frac{1998\times1996+1997\times11+1985}{1997\times1996-1995\times1996}\)

\(=\frac{1998\times1996+\left(1996+1\right)\times11+1985}{1996\times\left(1997-1995\right)}\)

\(=\frac{1998\times1996+1996\times11+11+1985}{1996\times2}\)

\(=\frac{1998\times1996+1996\times11+1996}{1996\times2}\)

\(=\frac{1996\times\left(1998+11+1\right)}{1996\times2}\)

\(=\frac{1996\times2010}{1996\times2}\)

\(=\frac{2010}{2}\)

\(=1005\)

a, \(2.3.4.8.50.25.125\)

\(=\left(2.50\right)\left(4.25\right)\left(8.125\right).3\)

\(=100.100.1000.3\)

\(=10000000.3\)

\(=30000000\)

b, \(45.128-90.64\)

\(=45.2.64-90.4\)

\(=90.64-90.64\)

\(=0\)

c, \(0,48.500-2,4.40.2\)

\(=0,48.100.5-2,4.2.10.4\)

\(=48.5-4,8.10.4\)

\(=48.5-48.4\)

\(=48\left(5-4\right)\)

\(=48.1\)

\(=48\) 

d, \(\frac{1998.1996+1997.11+1985}{1997.1996-1995.1996}\) \(\)

\(=\frac{1998.1996+\left(1996+1\right).11+1985}{1996\left(1997-1995\right)}\)

\(=\frac{1998.1996+1996.11+11+1985}{1996.2}\)

\(=\frac{1998.1996+1996.11+1996}{1996.2}\)

\(=\frac{1996\left(1998+11+1\right)}{1996.2}\)

\(=\frac{1998+11+1}{2}\)

\(=\frac{2010}{2}\)

\(=1005\)

C

C.75 min

⇒M=((x+3)2x2−9−189−x2+(x−3)2x2−9):2x+3

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