Verified answer

Ответ:

1.(х-12)²+24х

х²-24х+144+24х

х²+144

2.(х×9)²-х(х+8)

х²+18х+81-х²-8х

18х+81-8х

10х+81

3.(х+8)²-х(х+5)

х²+16х+64-х²-5х

16х+64-5х

11х+64