Question

Which expression is equivalent to 3n+2(1-4n)?

a) 2-n
b) 2-5n
c) 2+11n
d) 2-11n
Samuel chose A as his answer. Explain why he did that.

Answer 1

3n +2 -8n

2 - 5n

Explanation:

Answer 2

He only multiplied the 2 to the first term in the parentheses instead of both terms

Explanation:

3n+2(1-4n)

Distribute

3n + 2 -8n

Combine like terms

2 -5n

Samuel made the mistake of incompletely distributing

He only multiplied the 2 to the first term in the parentheses instead of both terms

3n+2(1-4n)

3n +2 -4n

2-n