спростіть вираз:

[tex]\ \textless \ br /\ \textgreater \ - 7xy {}^{2} \times 3x {}^{2}y {}^{3} \ \textless \ br /\ \textgreater \ \ \textless \ br /\ \textgreater \ [/tex]
а)
[tex]2ly {}^{5} {x}^{3} [/tex]
б)
[tex]21x {}^{2}y {}^{6} [/tex]
в)
[tex] - 21 {x}^{2}y {}^{6} [/tex]



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