Question

If the binary operation * on Z is defined by a * b = a² − b² + ab + 4, then value of (2 * 3) * 4 is ____________ .

विकल्प

• 233

• 33

• 55

• -55

Answer 1

33
Given:- a * b = a² − b² + ab + 4

\[2 * 3 = 2^2 - 3^2 + 2 \times 3 + 4\]
   \[ = 4 - 9 + 6 + 4\]
   \[ = 5\]
\[\left( 2 * 3 \right) * 4 = 5 * 4\]
    \[ = 5^2 - 4^2 + 5 \times 4 + 4\]
     \[ = 25 - 16 + 20 + 4\]
     \[ = 33\]