Question

If (p+q) =7 and pq=12, then ( p-q) ^2=

Answer 1

Answer:

$(p - q {)}^{2} = {p}^{2} + {q}^{2} - 2pq \\ = (p + q {)}^{2} - 4pq \\ when \:( p + q) = 7 \\ then \: (p + q {)}^{2} = {7}^{2} = 49 \\ pq = 12 \: then \: \: 4pq = 4 \times 12 = 48 \\ (p - q {)}^{2} = 49 - 48 = 1$