A store sells small notebooks for ​$8 and large notebooks for ​$16 . If a student buys 6 notebooks and spends ​$72 ​, how many of each size did he​ buy?

Respuesta :

8x+16y=72
x+y=6

x=6-y
8*(6-y)+16y=72
8y+48=72
8y=24
y=3
x=6-3=3
Answer: 3 of each size