📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!
  • google app store apple app store
    • ✖

      Question

      If x = 555, y = 554, z = 556, then the value of

      x2 + y2 + z2 - xy-yz-zx  
      A 2 Correct Answer Incorrect Answer
      B 3 Correct Answer Incorrect Answer
      C 4 Correct Answer Incorrect Answer
      D 5 Correct Answer Incorrect Answer
      E none of these Correct Answer Incorrect Answer

      Solution

      x2 + y2 + z2 - xy-yz-zx = 1/2 {(x-y)2+(y-z)2+(z-x)2 }  = 1/2 {(555-554)2+(554-556)2+(556-555)2 } = 1/2 {(1)2+(-2)2+(1)2 } = 1/2 (1 + 4 + 1) = 1/2 × 6 = 3

      Practice Next
      More Linear Equation Questions

      Relevant for Exams:

      ask-question