a, -31.52 + (-26).(-159)

=-31.2.26 + 26.159

= -62.26 + 26.159

= 26(-62 + 159)

= 26.97

= 2522

b, S=1-2+2²-2³+...+2¹⁰⁰⁰

2S=2-2²+2³-2⁴+...+2¹⁰⁰¹

S+2S=(1-2+2²-2³+...+2¹⁰⁰⁰)+(2-2²+2³-2⁴+...+2¹⁰⁰¹)

3S=1+2¹⁰⁰¹

S=\(\frac{1+2^{1001}}{3}\)

p=0-2+4-6+...+2010-2012

 =(0+4+.....+2010)-(2+6+...+2010)

 =507024-506018

 =1006

VAY P=1006

P=0-2+4-6+...+2010-2012=-2+-2-...+-2+-2=........

\(\Leftrightarrow\left(\frac{x-1}{2012}-1\right)+\left(\frac{x-2}{2011}-1\right)+...+\left(\frac{x-2012}{1}-1\right)=0\)

\(\Leftrightarrow\frac{x-2013}{2012}+\frac{x-2013}{2011}+...+\frac{x-2013}{1}=0\)

\(\Leftrightarrow\left(x-2013\right)\left(\frac{1}{2012}+\frac{1}{2011}+....+1\right)=0\)

\(\Leftrightarrow x-2013=0\)(because 1/2012 +1/2011+...+1 luôn lớn hơn 0

\(\Leftrightarrow x=2013\)

Vậy ........

1996 x 1995 - 996 / 1000 + 1996 x 1994 = 1996 x 1994 + 1996 - 996 / 1000 + 1996 x 1994

                                                           =      1996 x 1994 + 1000 / 1000 + 1996 x 1994 

                                                          =                        1

1996 x 1995 - 996 / 1000 + 1996 x 1994

= 3902020 - 0, 996 + 3980024

= 3902019, 004 + 3980024

= 7882043, 004

K nha PLEASE

\(\frac{1996\times1995-996}{1000+1996\times1994}\)

\(=\frac{1996\times\left(1995-1\right)+1996-996}{1000+1996\times1994}\)

\(=\frac{1996\times1994+1000}{1000+1996\times1994}\)

\(=1\)

1000+900=1900

1000+900=1900

tk mk nha các bn!!!!!!!!!!!!!!!!!!

1900  tk nha 

\(\left(\frac{3}{5}\right)^{12}\)

vậy ngày 27 tháng 2 năm 2013 là thứ tư

57/62

203 022

203022

= 203,022 bạn nhé