Question

If pq = 9 and p + q = 7, then p² + q² = ?
(a) 10
(b) 11
(c) 17
(d) 31​

Answer 1

$\underline{ \underline{\bf\red{Given-}}}$

$\bull \: \sf{pq = 9}$

$\sf \bull \: p + q = 7$

$\underline{ \underline{\bf\green{To \:Find-}}}$

$\sf{\bull \: p² + q² }$

$\underline{ \underline{\bf\blue{Solution -}}}$

$\underline {\text\pink{Formula\: Used -}}$

$\boxed{\sf{ \green{(a+b)^2} = \purple{a^2+b^2 + 2ab}}}$

$\underline {\text\pink{Similarily -}}$

$\sf(p+q)^2 = p^2+q^2+2pq$

$\sf{7^2 = p^2 + q^2 + 2 \times 9}$

$\: \: \: \: \: \: \: \: \: \: \: \: \quad \quad\quad\quad \sf{(putting \: values})$

$\sf49 =p^2 + q^2 +18$

$\sf{49-18 =p^2 + q^2 }$

$\sf31 = p^2 + q^2$

$\underline {\boxed{\sf\red{p^2 + q^2 =31}}}$

$\blue\therefore \text{Option (d) 31 is correct}$✔️

Answer 2

Answer:

mark above answer in brainliest.

Step-by-step explanation:

option (d) is right.