Expand: (a + 6)^2.
Note
Use (p + q)^2 = p^2 + 2pq + q^2. Here p = a and q = 6, so the middle term is 2 × a × 6 = 12a.
Expand: (a + 6)^2.
Use (p + q)^2 = p^2 + 2pq + q^2. Here p = a and q = 6, so the middle term is 2 × a × 6 = 12a.