Answer:
x=3 y=-1
Step-by-step explanation:
3x+2y=7
x-y=4
the third fifth and first
Answer: D. 
Step-by-step explanation:
Using exponent rules an exponent to the power of a number will multiply by each other.
So the -4 and -9 will multiply.
The 6 in the numerator will now have a positive exponent of 36.

Now we can divide and when we do so the exponents will subtract from each other.
So 36 - 6 = 30
And the base of 6 does not change.
The simplified form is 
Eighths and their multiples are common fractions which I recommend memorizing, but to actually solve this, you use the literal meaning of a fraction and divide 5 by 8. See the long-division below (it was surprisingly difficult to type, so I hope it helps!).
To round 0.625 to the nearest hundredth, we go to the second decimal place, which is 5, so we round up to 0.63.