\(\mathrm {a+b=7}\) এবং \(\mathrm {ab=12}\) হলে, \(\mathrm {\frac {1}{a^2} +\frac {1}{b^2}}\) এর মান কত?

  • \(\frac {3}{25}\)
  • \(\frac {25}{144}\)
  • \(\frac {31}{144}\)
  • \(\frac {11}{49}\)

41 bcs math question 11