Test 4 Section 9 - #7 (page 611)

OK, you're going to have to do some tricky solving for this one. Start by solving for x:

x^-½ = ⅓
x^½ = 3 (negative exponent means inverse)
x = 9 (square both sides to get rid of the ½ exponent)

You're also going to have to figure out y and z. The question says that z > y, so we can't go the obvious 4² route. Instead, we're going to have to say that z = 4 and y = 2. 2⁴ = 16 as well.

So, x = 9, and z = 4. x + z = 13. That's choice (D).