A student simplifies (6b + 4r) - (2b + r) and says that the result is 4b + 5r. Explain the error and describe the correct steps to simplify the expression.

The error is that the student didn't subtract the r but instead added an r

Step-by-step explanation:

Step 1: Distribute the negative

6b + 4r - 2b - r

Step 2: Combine like terms

4b + 3r

And we have our final answer!

see below

Step-by-step explanation:

(6b + 4r) - (2b + r)

Distribute the minus sign to all terms in the last parentheses

6b + 4r - 2b - r

Combine like terms

4b + 3r

They only subtracted the 2b and did not distribute the minus sign to both the 2b and the r

(6b + 4r) - (2b + r) = 6b + 4r - 2b+r = 4b+5r which is wrong