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Question

anonymous · Answer

for x = –1, y = 5, and z = 3.

dumbcow · Answer

straight substitution

aroub · Answer

just substitute -1 by x and 5 by y and 3 by z !! :)

anonymous · Answer

im lost

dumbcow · Answer

actually simplify it first then  substitute.
-5/15 = -1/3
x^3/x^-7 = x^(3+7) = x^10
y^5/y^5 = 1

anonymous · Answer

needs to = -9,-3,-1 or 0

anonymous · Answer

so im confuzed

dumbcow · Answer

have you ever divided variables with exponents ?
Ex:
whats x^4/x^2

anonymous · Answer

100

anonymous · Answer

if x is 10

dumbcow · Answer

correct...x^4/x^2 = x^(4-2) = x^2
10^2 = 100

dumbcow · Answer

so thats all you're doing here, combining variables by subtracting their exponents

anonymous · Answer

but i dont understand the answer

dumbcow · Answer

well after you combine variables, you have to plug in the given values for the variables just like you used 10 for x above.

anonymous · Answer

is it -1

dumbcow · Answer

$$\rightarrow \frac{-x^{10}}{3z^{-2}} = \frac{-x^{10}z^{2}}{3} = \frac{-(-1)^{10}(3)^{2}}{3} = \frac{(-1)(9)}{3} = -3$$

anonymous · Answer

ty