1)37a+83a=120a=120*8=960
2) 82b-28b= 54b=54*32=1728
3) 33c-6c-7c=20c=20*549=10980
4)17x-8x+31x-18=40x-18=(40*312)-18=12792-18=12774
Пошаговое объяснение:
37a+83a=100a+20a=800+160=960
82b-28b=10b+10b+10b+10b+10b+4b=320+320+320+320+320+128=1728
33c-6c-7c=20c=10c+10c=5490+5490=10980
40x-19= 10x+10x+10x+10x-18=3120+3120+3120+3120-18=12462
