What value of x makes this a right triangle ?

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

    choose the correct definition for  extremo.  a.  end      b.  extra      c.  extract      d.  eventual 

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)