Clara simplifies open paren 8 b minus 4 r close paren minus open paren 2 b minus r close paren and says the result is 6 b minus 5 r What error did Clara make?

Distribute the subtraction across the second parentheses: (8b − 4r) − (2b − r) = 8b − 4r − 2b + r. Combine like terms to get 6b − 3r, so Clara’s error was combining the r coefficients incorrectly.

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