Fractions with exponents and multiplying exponents

Question

Simplify the following expressions. Final answer should contain positive exponents only.

1. 2xy-6xy-2x+5x
2. x^2/x^5
3. (a^3 b^2) (a^5 b^-5)
4. 3x^4 y^2 / 9xy^6
5. (3xy^3)^3(2x)

I dont understand these which is most of my homework and i need help

Answer 1

1. 2xy-6xy-2x+5x -> add or subtract like terms, so xy coefficients get added 2-6 and x coefficients get added -2+5
2. x^2/x^5 -> the difference between the exponents is determined and then the result will be in the position of the larger exponent, 1/x^3
3. (a^3 b^2) (a^5 b^-5) -> when multiplying exponents the powers will be added a^(3+5) * b^(2-5) then the negative exponents moved up or down depending on where it started => a^8/b^3
4. 3x^4 y^2 / 9xy^6 -> when dividing exponents the powers are subtracted, you can subtract the lower exponent from the higher and then place the exponent where the higher was previously => x^3/3y^4
5. (3xy^3)^3(2x) -> when raising an exponent to a power, the coefficients and powers are multiplied, (y^3)^3 => y^9 and (3x)^3 => 27x^3