Answer:
Clara incorrectly combined the r coefficients. The correctly simplified expression is 6 b minus 3 r.
Explanation:
(8b-4r)-(2b-r)
Open the bracket
=8b-4r-2b+r
Collect the like terms and simplify
=8b-2b-4r+r
=6b-3r
Clara incorrectly combined the r coefficients. The correctly simplified expression is 6 b minus 3 r.