\(8,64\times46+52\times8,64+17,28\)

\(=8,64\times46+52\times8,64+8,64\times2\)

\(=8,64\times\left(46+52+2\right)\)

\(=8,64\times100=864\)

\(26+5x=3x+56\)

\(\Rightarrow5x-3x=56-26\)

\(\Rightarrow2x=30\)

\(\Rightarrow x=30:2\)

\(\Rightarrow x=15\)

Vậy \(x=15\)

 Tớ không thấy đề bài cậu ơi!

\(24.\left[18-\left(3^2-2\right)^2\right]\)

\(=24.\left[18-\left(9-2\right)^2\right]\)

\(=24.\left[18-7^2\right]\)

\(=24.\left[18-49\right]\)

\(=24.-31=-744\)

`987`\(\times34+65\times987+978+9\)

\(=987\times\left(34+65\right)+978+9\)

\(=987\times99+978+9\)

\(=97713+978+9\)

\(=98691+9=98700\)

Hbth cop AI => ghi TK ah!

\(Ư\left(15\right)=\left\{1;3;5;15\right\}\)

Mở rộng : \(Ư\left(15\right)=\left\{\pm1;\pm3;\pm5;\pm15\right\}\)

\(81:3^2+5\times4^2-7\times3^2\)

\(=81:9-5\times16-7\times9\)

\(=9-80-63\)

\(=-71-63=-134\)

\(x^2=144\)

\(\Rightarrow x^2=\left(\pm12\right)^2\)

\(\Rightarrow x\in\left\{\pm12\right\}\)

\(a=23\times23=529\)

$\Rightarrow$\(x=123\times4+529\)

\(\Rightarrow x=492+529=1021\)