vbuiglllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll

 = 900 00 + 900 0001 + 900 002 + 900 0003 + 900 004 + 900 005+ ... + 1 000 000 + 1 000 001 + 1 000 0002 + 1 000 003 + 1 000 004 + 1 000 005 nhé bn

91-273:3=91-91=0

=>(1²+2²+3²+...+100²)(91-273:3)=(1²+2²+3²+...+100²).0=0

7 . (-2)^3 - 60:15

= 7 . (-8) - 4

= (-56)- 4

= - 60

125 - (-75) + 32 - (48 + 32)

= 125-75 + 32 - 48 -32

=  50 + (-48)

=2

= 19 + (-20) + (-19)+12

= 19+(-19) + (-20)+12

= 0+ (-8)

= -8

91 -273:3=91-91=0 

Ta có : \(1^2+2^2+3^2+.....+10^2=385\)

\(\Leftrightarrow2^2\left(1^2+2^2+3^2+.....+10^2\right)=2^2.385\)

\(\Leftrightarrow2^2+4^2+6^2+.....+20^2=4.385\)

\(\Leftrightarrow2^2+4^2+6^2+.....+20^2=1540\)

Sửa đề: CHo 1²+2²+...+10²=385. Tính S = 2²+4² +...+ 20²

S = 2² + 4² +...+ 20²

= (1.2)² + (2.2)² +...+ (2.10)²

= 1².2² + 2².2² +...+ 2².10²

= 2²(1² + 2² +...+ 10²)

= 4.385

= 1540

S= 1^2  .  2^2 + 2^2 . 2^2  + ... + 10^2 . 2^2
  = 4. ( 1^2 + 2^2 +...+ 10^2)  = 4 . 385 = 1540

chúc bạn học giỏi

(1²+2²...+1000²).(91-273:3)

=(1²+2²...+1000²).(91-91)

=(1²+2²...+1000²).0

=0

= 50

Nho t ick nha

     \(\left(102+82+62+42+22\right)-\left(12+32+53+72+92\right)\)

\(=102+82+62+42+22-12-32-52-72-92\)

\(=\left(102-92\right)+\left(82-72\right)+\left(62-52\right)+\left(42-32\right)+\left(22-12\right)\)

\(=10+10+10+10+10\)

\(=10.5\)

\(=50\)

\(\frac{12}{15}\times\frac{22}{47}+\frac{25}{47}:\frac{15}{12}\)

\(\frac{12}{15}\times\frac{22}{47}+\frac{25}{47}\times\frac{12}{15}\)

\(=\frac{12}{15}\times\left(\frac{22}{47}+\frac{25}{47}\right)\)

\(=\frac{12}{15}\times\frac{22+25}{47}\)

\(=\frac{12}{15}\times1=\frac{12}{15}\)