Judy read 1/2 (one-half) of the total book on Friday night. On Saturday night, she read 2/7 (two-seventh) of the total book. What fraction of the total book does she have left to read?

So the queston is asking 1/2+2/7+x=1/1=whole book

to add fractions, we must make sure that the denomenators are the same sso

1/2=7/14

2/7=4/14

7/14+4/14=11/14

11/14+x=14/14

subtract 11/14 from both sides

x=3/14

3/14 of the book left to read