Xiao Li has (x-4.6) yuan and Xiao Ming has (x-3.6) yuan.

Two people * * * have (x-4.6)+(x-3.6) yuan, which is 2x-8.2 yuan money.

I just bought a book. That is, x=2x-8.2.

X=8.2 yuan. So the price of this book is 8.2 yuan.