pleaseee help meee with these

Answer:
6.
20+12=32
32+18=50
7. 15+15+15+15=60
S+S+S+S=60
8. S+S+S+S=100
25+25+25+25=100
9. 45+45=90
10+10=20
90+20=110
10. 16+16=32
32+15=47
47+20=67
Step-by-step explanation:
S- Is side but in a short word
Or you can use multiplication if you don't want addition