Question

If $x^{\ast }y=x+y+\sqrt{xy},$ find the value of $9^{\ast }64$.

• A. $97$ or $49$
• B. $-97$ or $49$
• C. $97$
• D. $-97$ or $-49$

Answer 1

The correct option is C $97$

$x\ast y=x+y+\sqrt{xy}$

$9\ast 64=9+64+\sqrt{9\times 64}$

$=73+24$

$=97$