Question

if p+q=12,pq=22,thenp square+q square

Answer 1

(p+q)² =12²
p²+q²+2pq=144
p²+q²=144-2pq
p²+q²=144-2×22
p²+q²=144-44
p²+q²=100

Answer 2

$P+q =12\\pq=22\\p^2+q^2=(p+q)^2-2pq\\=(12)^2-2.22\\=144-44\\=100$ we know,
$(a + b)^2 = a^2 + b^2 + 2ab \\(a+b)^2 - 2ab =a^2+b^2$
Use this here,