Question

If (p+q)=7 and pq=12 evaluate (p-q)²

Answer 1

Answer:

(p+q)=7.

pq=12.

Squaring on both sides,

(p+q)²=7².

p²+2pq+q²=49

p²+q²+24=49

p²+q²=25.

Therefore, (p-q)²=

p²-2pq+q²

(p²+q²)-(2pq)

25-12

13.

=(p-q)²=13.