Question

which statement explains why 49 is a perfect square?

49 can be multiplied by 49.
49 is equal to 7 plus 7.
49 is between 36 and 64.
49 is equal to 7 times 7.

Explanation:

Define a perfect square

$$ n = k^2 = k \times k \quad (k \in \mathbb{Z}) $$

Apply definition to 49

$$ 49 = 7^2 = 7 \times 7 $$

Answer:

• 49 can be multiplied by 49.
• 49 is equal to 7 plus 7.
• 49 is between 36 and 64.
• 49 is equal to 7 times 7. (Correct answer)