Answer:
D. 7(1+3)
Step-by-step explanation:
7+21
You split it into two factors using the distributive property. The common factor in both is 7.
7 goes into itself once, and goes into 21 three times. Thats where the 1 and 3 come from.
Answer:
28
Step-by-step explanation:
7 + 21 can be rewritten as 7(1 + 3), or 7(4), or 28
