Question

simplify: 3 to fourth power minus square root of sixty-four divide (10-12 squared)

Answer 1

Break it up and it'll be easier:
(3x3)x(3x3) (it doesn't matter where the x goes--it's all times the same positive number.
So (9x9)-sq. root of 64 (an easy one--it's got to be under 10n because you don't need the sq root of 100) over (10-12) x itself

Answer 2

x/7+y/15=3
x/2-y/5=4

Answer 3

2(3-5)