1.) y^6 / y^2 = y^4. To divide exponents with the same base, you just subtract. This does not apply if they have different bases (for example, if it were x^6 / y^2)
2.) z = x^2 + 2y^2
z = (-1)^2 + 2(5)^2
z = 1 + 2(25)
z = 1 + 50
z = 51
3.) 47 - 9x = 11
-9x = 11 - 47
-9x = -36
x = -36/-9
x = 4
