Help Please this is hard!!

20 ! need which shows a difference of squares? 10y^2-4x^2 16y^2-x^2 8x^2-40x+25 64x^2-48x+9

Which function families have maximums and minimums? 1.)linear absolute value functions and exponential functions 2.) linear absolute value functions and quadratic functions 3.) linear absolute value functions and linear functions 4.) linear absolute value functions and constant functions

The border line of the linear inequality 4x + 7y < 5 is dotted true or false?