Two binary operations \(\ast\) and \(\oplus\) are defines as m \(\ast\) n = mn - n - 1 and m \(\oplus\) n = mn + n - 2 for all real numbers m, n.

Find the value of 3 \(\oplus\) (4 \(\ast\) 50)

  • A 60
  • B 57
  • C 54
  • D 42
jamb 1997mathematics

The correct answer is C. 54

m \(\ast\) n = mn - n - 1, m \(\oplus\) n = mn + n - 2

3 \(\oplus\) (4 \(\ast\) 5) = 3 \(\oplus\) (4 x 5 - 5 - 1) = 3 \(\oplus\) 14

3 \(\oplus\) 14 = 3 x 14 + 14 - 2

= 54

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