Step 1
From the question;

We are required to find how many months it will take him to read 90 books
Step 2
We will use the ratio below to solve the problem.

Answer; It will take Bobby 9months to read 90 booj
4v
You would subtract 10-6
Then you would add the v
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You can write both numbers as fractions:

Dividing by a fraction is the same as multiplying by its inverse, so we have

We can cross-simplify the 10's and we have


Let's solve for x ~




Therefore, the possible values of x are 0 and 3