20x+ 15(32-x)=565
20x+480- 15x=565
20x- 15x=565-480
5x=85
x= 17
(32-x)=32- 17= 15
A: The students rented 17 and 15 boats.
2. Solution: If the number of ships is X, then the number of large ships is1.5x..
15x+20× 1.5x=360
15x+30x=360
45x=360
x=8
1.5x = 1.5×8 = 12
Answer; The students rented 12 big boat and 8 small boats.
3. Solution: If the number of ships is X, then the number of large ships is1.5x..
15x+20× 1.5x=680
15x+30x=680
45x=680
x= 15
1.5x = 1.5× 15 = 23
Answer; The students rented 15 big boat and 23 small boats.
4. Solution: X ships have been chartered, and this big ship has1.5x.
20× 1.5x = 15x+ 180
30x= 15x+ 180
30x- 15x= 180
15x= 180
x= 12
1.5x = 1.5× 12 = 18
A: The students rented 18 big boat and 12 small boat.