Question

please expand this in details in 5mins

Answer 1

$(m + 2n + 3r)^2 = m^2 + 4n^2 + 9r^2 + 4mn + 6mr + 12nr$

Answer 2

NOTE: (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca

→ (m + 2n + 3r)²

→ (m)² + (2n)² + (3r)² + 2(m)(2n) + 2(2n)(3r) + 2(3r)(m)

→ m² + 4n² + 9r² + 2(m)(2n) + 2(2n)(3r) + 2(3r)(m)

→ m² + 4n² + 9r² + 4mn + 12nr + 6mr

Hope it helps!!