Question

what is the value of 2(p2+q2) if p+q=7 and p-q=3? please explain (i wrote p2 which means p square and q2 means q square)

Answer 1

Answer:

if p + q = 4 and p^2 + q^2 = 7 then the value of pq is

Answer 2

Answer:

$2(p^2 + q^2) = 58$

Step-by-step explanation:

Given that, p + q = 7

∴ $(p + q)^2 = 7^2$  [squaring both sides]

$=> p^2 + 2pq + q^2 = 49$ . . . . . . . . . . . . . . (i)

Also given that, p - q = 3

∴ $(p - q)^2 = 3^2$  [squaring both sides]

$=> p^2 - 2pq + q^2 = 9$ . . . . . . . . . . . . . . . (ii)

Adding equation (i) and (ii):

$=> 2p^2 + 2q^2 = 58$

$=> 2(p^2 + q^2) = 58$