3x+4(x-36)=248
7x- 144=248
7x=392
Solution:
x=56
So every schoolbag 56 yuan, every dictionary 20 yuan.
(2) If there are 40 people in the class with Y schoolbags, then the dictionaries of (40-y) people can be classified as an unequal group:
1500-360≤56y+20(40-y)≤ 1500-250
1 140≤36y+800≤ 1250
340≤36y≤450
340≤36y≤450
85/9≤y≤25/2
Because y is an integer, the values of y are 10, 1 1, 12.
So * * * there are three schemes:
Buy 10 schoolbag and 30 dictionaries;
Purchase 1 1 schoolbag and 29 dictionaries;
Buy 12 schoolbag and 28 dictionaries.