hello pls help pls how do i write this out pls explain

Question

There were 1670 English and Chinese books in a bookshop. During a weekend sale, 7/10 of the English books and 3/4 of the Chinese books were sold.

The bookshop was left with 462 books. How many books of each type were sold?

Answer 1

e + c = 1670

7e/10 + 3c/4 = 1670-462= 1208

7(1670-c)/10 +3c/4 = 1208

multiply by 4(10)

7(4)(1670) -7(4)c + 3(10)c = 1208(4)(10)

2c = 1208(40)-1670(28)

c = 604(40)-835(28)

c= 24160 - 23380

c= 780 chinese books

e =1670-780= 890 english

7e/10=7(89)= 623 english left

890-623= 267 english sold

1208-623=585 chinese left

780-585=195 chinese sold

3c/4=3(780)/4=3(195)= 585