If ty > 0 and yz < 0, which of the following must be negative:  Choose the correct answer:	A) tyz	B) ty(z^2)	C) t(y^2)z	D) t(y^2)(z^2)	E) (x^2)(y^2)(z^2)
ty &gt; 0 means that ty is positive.   yz &lt; 0 means that yz is negative.   t(y^2)z = (ty)(yz) = positive*negative = negative. Thus option t(y^2)z is always negative.
<result>C</result>
If ty > 0 and yz < 0, which of the following must be negative: