Question

if p=3/4 of q and p=2/3 + 5/6 then p +q is
a)21/24
b)9/8
c)21/8
d)23/8​

Answer 1

Answer:

if p=3/4 of q and p=2/3 + 5/6 then p +q is

a)21/24

b)9/8

c)21/8

d)23/8

Answer 2

Using the identity is (a+b)3=a3+b3+3ab(a+b)

Consider,

(p+q)3=p3+q3+3pq(p+q)

 

It is given that p+q=5 and pq=6, therefore,

(p+q)3=p3+q3+3pq(p+q)⇒(5)3=p3+q3+(3×6)(5)⇒125=p3+q3+(18×5)⇒125=p3+q3+90⇒p3+q3=125−90⇒p3+q3=35

Hence, p3+q3=35.