Question : If $3x-2y=3$ and $xy=9$, then find the value of $3x+2y$.
Option 1: 16
Option 2: 13
Option 3: 14
Option 4: 15
New: SSC CHSL Tier 2 answer key released | SSC CHSL 2024 Notification PDF
Recommended: How to crack SSC CHSL | SSC CHSL exam guide
Don't Miss: Month-wise Current Affairs | Upcoming government exams
Correct Answer: 15
Solution :
Given, $3x-2y=3$ and $xy=9$
Consider, $3x-2y=3$
Squaring both sides, we get,
$(3x-2y)^2=3^2$
⇒ $9x^2+4y^2-12xy=9$
Adding $24xy$ on the both sides, we get,
⇒ $9x^2+4y^2-12xy+24xy=9+24xy$
⇒ $(3x+2y)^2+12xy=9+24xy$
⇒ $(3x+2y)^2=9+24\times 9$
⇒ $(3x+2y)^2=9+219$
⇒ $(3x+2y)=\sqrt{225}$
⇒ $(3x+2y)=15$
Hence, the correct answer is 15.
Related Questions
Know More about
Staff Selection Commission Combined High ...
Result | Eligibility | Application | Admit Card | Answer Key | Preparation Tips | Cutoff
Get Updates Brochure
Your Staff Selection Commission Combined Higher Secondary Level Exam brochure has been successfully mailed to your registered email id “”.
