№1
(750800-6248+55448):100-800=7200
1.750800-6248=744552
2. 744552+55448=800000
3. 800000:100=8000
4. 8000-800=7200
№2
361894*(15468-6800-8667)=361894
1.15468-6800=8668
2. 8668-8667=1
3. 361894*1=361894
№3
1000000:(670320+329980-300)=1
1. 670320+329980=1000300
2. 1000300-300=1000000
3. 1000000:1000000=1