Đề khó nhìn quá bạn ơi!

Sửa đề (1 + 2² + 3³ +...+2015²⁰¹⁵).(4.35 - 2.70).(1/2+1/6+1/12+1/30) 

=  (1 + 2² + 3³ +...+2015²⁰¹⁵).(140 - 140).(1/2+1/6+1/12+1/30) 

=  (1 + 2² + 3³ +...+2015²⁰¹⁵).0.(1/2+1/6+1/12+1/30) 

= 0

\(\frac{5^3.3^5}{5^3.0,5+125.2,5}\)

\(=\frac{5^3.3^5}{5^3.0,5+5^3.2,5}\)

\(=\frac{5^3.3^5}{5^3\left(0,5+2,5\right)}\)

\(=\frac{5^3.3^5}{5^3.3}\)

\(=3^4=81\)

#Học tốt!!!

~NTTH~

B=1-2-3+4+5-6-7+8+..........+21-22-23+24

B=(1-2-3+4)+(5-6-7+8)+.......+(21-22-23+24)

B=0+0+............+0

B=0

[ -1+2] + [ 3-4-5+6 ]  + [ 7-8-7+10 ] +  [ 11-12-13+14 ] + ................+  99-100-101

= 1 + 0+0+0+0+...............+-102

= -101

thank you bạn đã ra câu hỏi và bạn đã ra câu trả lời

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

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