Упр.10.22 ГДЗ Мерзляк Поляков 7 класс (Алгебра)

1) ?cab+?ca;
2) ?abc+?bca;
3) ?ab9+?7a.

1) $$\overline{cab}+\overline{ca}=100c+10a+b+(10c+a)$$

$$=100c+10a+b+10c+a=110c+11a+b.$$

2) $$\overline{abc}+\overline{bca}=100a+10b+c+(100b+10c+a)$$

$$=100a+10b+c+100b+10c+a=101a+110b+11c.$$

3) $$\overline{ab9}+\overline{7a}=100a+10b+9+(70+a)$$

$$=100a+10b+9+70+a=101a+10b+79.$$

Ответ

1) $$110c+11a+b$$

2) $$101a+110b+11c$$

3) $$101a+10b+79$$