Question

if p²+q²=5
pq=2
find p³- q³
​

Answer 1

Step-by-step explanation:

(p-q)^2=p^2+q^2-2pq

=5-2*2=5-4=1

p-q=1 or p-q=-1

p

(p-q)^3=p^3-3p^2q+3pq^2-q^3

p^3-q^3=(p+q)^3+3pq(p-q)

putting p-q=1

p^3-q^3=1+6(1)=7

putting p-q=-1

p^3-q^3=-1+3(2)(-1)=-1-6=-7