Factor the expression: -12x - 16y

What expression is equivalent to 42x-56y

Ametal rod needs to be 9 feet and 5.5 inches in length. the sections of the poles being used are each 1 foot and 10.5 inches long. how many 1ft 10.5in sections would be needed to complete the 9ft 5.5in metal rod? and how many inches of material will be left?

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