1) x + y > y
according to the places where x and y is placed y is greater than x and x + y will make a larger negative number so it cant be true.
take x = -0.5 and y = -0.3

2) xy > xz
x and y are begative so their multiplication will be positive and as z is positive multiplication of xz will be negative, cant be true.
take x = -0.5, y = -0.3 and z = 0.3

3)tz < z
both t and z are positive and t is greater than z, so tz will be greater than z.

4) m^u < 0
m = -1 and u = 2
m^u = 1, can't be true.

5) t^m > 0
here m = -1 and t is number which is between 1 and 2, to get such a number the denominator will always be less than numerator and now if we try to find out, the raise to -1 of this number, this will be always a positive number and greater than zero.

Please comment.
Ans E.

Not sure what u did not undersand in this one. But if you find it difficult to deal with variables, just assign numbers and solve. So in this case u have answered

XZ > XY, but this is not possible as XZ is a negative number (-ve * + ve) wile XY is a positive number. So XZ will always be smaller thanXY

The answer is t^m > 0. Since t is +ve. t^-1 = 1/t. This number will always be positive >0