If a2 + 4b2 + 49c2 + 18 = 2 (2b + 28c – a), then the value of (3a + 2b + 7c) is:

This question was previously asked in
SSC CHSL Previous Paper 12 (Held On: 2 Jul 2019 Shift 1)
View all SSC CHSL Papers >
  1. 1
  2. 0
  3. 2
  4. 3

Answer (Detailed Solution Below)

Option 3 : 2
Free
SSC CHSL General Intelligence Sectional Test 1
1.7 Lakh Users
25 Questions 50 Marks 18 Mins

Detailed Solution

Download Solution PDF

a2 + 4b2 + 49c2 + 18 = 2 (2b + 28c – a)

⇒ a2 + 4b2 + 49c2 + 18 = 4b + 56c – 2a

⇒ (a2 + 2a + 1) + (4b2 – 4b + 1) + (49c2 – 56c + 16) = 1 + 1 + 16 – 18

⇒ (a + 1)2 + (2b – 1)2 + (7c – 4)2 = 0

⇒ a + 1 = 0, 2b – 1 = 0, 7c – 4 = 0

⇒ a = -1, b = ½, c = 4/7

(3a + 2b + 7c) = (3 × (-1) + 2 × (1/2) + 7 × (4/7)) = -3 + 1 + 4 = 2

Latest SSC CHSL Updates

Last updated on Jul 22, 2025

-> The Staff selection commission has released the SSC CHSL Notification 2025 on its official website.

-> The SSC CHSL New Application Correction Window has been announced. As per the notice, the SCS CHSL Application Correction Window will now be from 25.07.2025 to 26.07.2025.   

-> The SSC CHSL is conducted to recruit candidates for various posts such as Postal Assistant, Lower Divisional Clerks, Court Clerk, Sorting Assistants, Data Entry Operators, etc. under the Central Government. 

-> The SSC CHSL Selection Process consists of a Computer Based Exam (Tier I & Tier II).

-> To enhance your preparation for the exam, practice important questions from SSC CHSL Previous Year Papers. Also, attempt SSC CHSL Mock Test.  

->UGC NET Final Asnwer Key 2025 June has been released by NTA on its official site

->HTET Admit Card 2025 has been released on its official site

Get Free Access Now
Hot Links: teen patti star teen patti 51 bonus teen patti royal