Question

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

Answer 1

Here you go! It's correct.

Explanation:

The student did not distribute the negative when subtracting. Distributing the negative, the expression is equal to 6b + 4r – 2b – r. Then use the commutative property to rewrite it as 6b – 2b + 4r – r. Then you can use the distributive property to write as (6 – 2)b + (4 – 1)r, which simplifies to 4b + 3r.