B+179-89=b+90=b
b+90=b+90=b
b-любое число,я так думаю
1)637 637:7=91 091
2)91 091:11=8 281
3)8 281:13=637
4)637*1001=1 638
ответ1 638
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
4 5/6 - 2 23/24 = 4 20/24 - 2 23/24 = 1 21/24 = 1 7/8
7 - 2 16/12 = 7 - 3 4/12 = 3 8/12 = 3 2/3
(-0.7х+0.6у)5-3(0,4у-1.5х)=-3.5х+3у-1.2у+4.5х=х+1,8у
20*5=100дм² покрасит Вася за 5мин
15*7=105дм² покрасит Дима за 7мин
105>100
не сможет