cho mk đúng ko

Giải:
Ta có:
a^2014 + b^2014 + c^2014 = a^1007b^1007 + b^1007c^1007 + c^1007a^1007
=> 2(a^2014 + b^2014 + c^2014) = 2(a^1007b^1007 + b^1007c^1007 + c^1007a^1007)
=> ( a^1007 - b^1007 )^2 + (b^1007 - c^1007)^2 + ( c^1007 - a^1007)^2 = 0
=> a - b - c = 0
Vậy A = 0

Giải:
Ta có:
a^2014 + b^2014 + c^2014 = a^1007b^1007 + b^1007c^1007 + c^1007a^1007
=> 2(a^2014 + b^2014 + c^2014) = 2(a^1007b^1007 + b^1007c^1007 + c^1007a^1007)
=> ( a^1007 - b^1007 )^2 + (b^1007 - c^1007)^2 + ( c^1007 - a^1007)^2 = 0
=> a - b - c = 0
Vậy A = 0

Ta có:
a²⁰¹⁴ + b²⁰¹⁴ + c²⁰¹⁴ = a¹⁰⁰⁷b¹⁰⁰⁷ + b¹⁰⁰⁷c¹⁰⁰⁷ + c¹⁰⁰⁷a¹⁰⁰⁷
\(\Rightarrow\) 2(a²⁰¹⁴ + b²⁰¹⁴ + c²⁰¹⁴) = 2(a¹⁰⁰⁷b¹⁰⁰⁷ + b¹⁰⁰⁷c¹⁰⁰⁷ + c¹⁰⁰⁷a¹⁰⁰⁷)
\(\Rightarrow\) ( a¹⁰⁰⁷ - b¹⁰⁰⁷ )² + (b¹⁰⁰⁷ - c¹⁰⁰⁷)² + ( c¹⁰⁰⁷ - a¹⁰⁰⁷)² = 0
\(\Rightarrow\) a - b - c = 0
Vậy A = 0

   Đây là cách 1:

     A = 2014.(2015 - 37) - 100.(-76 + 4030)

=> A = 2014. 2015 - 2014. 37 + 1007. 76 - 1007. 4030

=> A = 1007. 2. 2015 - 1007. 2. 37 + 1007. 76 - 1007. 4030

=> A = 1007. 4030 - 1007. 74 + 1007. 76 - 1007. 4030

=> A = ( 1007. 4030 - 1007. 4030 ) + ( 1007. 76 - 1007. 74)

=> A =                      0                 +     1007.( 76 - 74 )

=> A =                      0                 +       1007 . 2

=> A =                                     2014 

Vậy A = 2014

Và đây là cách 2: ( Hai cách hơi giống nhau nên các bạn thông cảm )

     A = 2014. (2015 - 37) - 1007. (-76 + 4030)

=> A = 2014. 2015 - 2014. 37 + 1007. 76 - 1007 . 4030

=> A = 2014. 2015 - 2014. 37 + 1007. 2. 38 - 1007. 2. 2015

=> A = 2014. 2015 - 2014. 37 + 2014. 38 - 2014. 2015

=> A = ( 2014. 2015 - 2014. 2015 ) + ( 2014. 38 - 2014. 37 )

=> A =                    0                   +     2014. ( 38 - 37 )

=> A =                    0                   +       2014. 1

=> A =                                     2014

Vậy A = 2014

a) \(\left( {\frac{7}{3} + 3,5} \right):\left( { - \frac{{25}}{6} + \frac{{22}}{7}} \right) + 0,5\)

\(\begin{array}{l} = \left( {\frac{7}{3} + \frac{7}{2}} \right):\left( { - \frac{{25}}{6} + \frac{{22}}{7}} \right) + \frac{1}{2}\\ = \frac{{35}}{6}:\frac{{ - 25.7 + 22.6}}{{6.7}} + \frac{1}{2}\\ = \frac{{35}}{6}:\frac{{ - 43}}{{7.6}} + \frac{1}{2} = \frac{{35}}{6}.\frac{{7.6}}{{ - 43}} + \frac{1}{2}\\ = \frac{{ - 245}}{{43}} + \frac{1}{2} = \frac{{ - 245.2 + 43}}{{43.2}} = \frac{{ - 447}}{{86}}\end{array}\)

b) \(\frac{{38}}{7} + \left( { - 3,25} \right) - \frac{{17}}{7} + 4,55\)

\(\begin{array}{l} = \left( {\frac{{38}}{7} - \frac{{17}}{7}} \right) + \left( {4,55 - 3,25} \right)\\ = \frac{{38 - 17}}{7} + 1,3 = \frac{{21}}{7} +1,3\\ = 3 + 1,3 =  4,3\end{array}\)

a)

 \(\begin{array}{l}\left( {0,25 - \frac{5}{6}} \right).1,6 + \frac{{ - 1}}{3}\\ =(\frac{25}{100}-\frac{5}{6}).\frac{16}{10}+\frac{-1}{3}\\= \left( {\frac{1}{4} - \frac{5}{6}} \right).\frac{8}{5} + \frac{{ - 1}}{3}\\ = \left( {\frac{6}{{24}} - \frac{{20}}{{24}}} \right).\frac{8}{5} + \frac{{ - 1}}{3}\\ = \frac{{ - 14}}{{24}}.\frac{8}{5} + \frac{{ - 1}}{3}\\ = \frac{{ - 14}}{{15}} + \frac{{ - 1}}{3}\\ = \frac{{ - 14}}{{15}} + \frac{{ - 5}}{{15}}\\ = \frac{{ - 19}}{{15}}\end{array}\)

b)

\(\begin{array}{l}3 - 2.\left[ {0,5 + \left( {0,25 - \frac{1}{6}} \right)} \right]\\ = 3 - 2.\left[ {\frac{1}{2} + \left( {\frac{1}{4} - \frac{1}{6}} \right)} \right]\\ = 3 - 2.\left( {\frac{1}{2} + \frac{1}{{12}}} \right)\\ =3-2.(\frac{6}{12}+\frac{1}{12})\\= 3 - 2.\frac{7}{{12}}\\ = 3 - \frac{7}{6}\\=\frac{18}{6}-\frac{7}{6}\\ = \frac{{11}}{6}\end{array}\)

\(\Rightarrow A=\frac{\frac{1}{2}-\frac{1}{5}+\frac{1}{7}}{\frac{3}{8}-\frac{3}{5}+\frac{3}{7}}+\frac{\frac{1}{2}+\frac{1}{3}-\frac{1}{5}}{\frac{3}{4}+\frac{1}{2}+\frac{3}{10}}\)

\(\Rightarrow A=\frac{\frac{1}{2}-\frac{1}{5}+\frac{1}{7}}{3.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{7}\right)}+\frac{\frac{1}{2}+\frac{1}{3}-\frac{1}{5}}{\frac{3}{2}.\left(\frac{1}{2}+\frac{1}{3}-\frac{1}{5}\right)}\)

\(\Rightarrow A=\frac{1}{3}+\frac{2}{3}\)

\(\Rightarrow A=1\)

a) \(log_50,5=-0,439677\)

c) \(In\left(\dfrac{3}{2}\right)=0,405465\)

bài 1 :

tự làm