Answer:
any number except -20
Step-by-step explanation:




Multiply by -1 to make the k positive. This will alter all the terms which means 20 will become negative. NOTE: When multiplying or dividing by negative numbers, the inequaliy sign flips.

k must be either greater than -20 but not including it or fewer than -20 but not including it; therefore, any number between negative infinity and -21 and -19 and postive infinity
Look a view at this picture
here 8x and (2x+60) are corresponding angles
since line l1 and l2 are parallel, so the two angles will be equal
8x=2x+60
8x-2x=60
6x=60
dividing by 6
x=10
option D. 10 is correct