Question

Show that 5 × 7 × 11 × 13 + 55 is a composite number.

Answer 1

Explanation:

5 * 7 * 11 * 13 + 55

= 5 * 7 * 11 * 13 + (5 * 11)

= 5 * 11 * (7 * 13 + 1)

Since there are other factors besides 1 and itself (5, 11, etc.), it is a composite number. (Shown)