Write an expression that is equivalent to the following x + x + x + - 20

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

Gabriel determined that his total cost would be represented by 2.5x + 2y – 2. his sister states that the expression should be x + x + 0.5x + y + y – 2. who is correct? explain.

Lowest fraction using common term 28/35