Question

1. which expression represents \the difference of twenty - one and six, then divide by three\?

a) 21 ÷ (6 ÷ 3)
b) 21 - (6 ÷ 3)
c) (21 + 6) ÷ 3
d) (21 - 6) ÷ 3

1. write \the sum of 6 and 12 subtracted from 30\ as a numerical expression.

Explanation:

Step1: Analyze Question 5

First, "the difference of twenty-one and six" means $21 - 6$. Then "divide by three" means we divide the entire difference by 3, so we need parentheses around the subtraction: $(21 - 6) \div 3$. We check each option:

• A) $21 \div (6 \div 3)$: Divides 21 by the result of 6÷3, not matching.
• B) $21 - (6 \div 3)$: Subtracts 6÷3 from 21, not matching.
• C) $(21 + 6) \div 3$: Uses sum instead of difference, not matching.
• D) $(21 - 6) \div 3$: Matches the described operation.

Step2: Analyze Question 10

"the sum of 6 and 12" is $6 + 12$. "subtracted from 30" means we take 30 minus that sum, so the expression is $30 - (6 + 12)$.

Answer:

1. D) $(21 - 6) \div 3$
2. $30 - (6 + 12)$