PLEASE I NEED THESE 4 ANSWERED ASAP :))

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

What is perpendicular to y=-1/2x+11

Aresearch study is done to find the average age of all u. s. factory workers. the researchers asked every factory worker in ohio what their birth year is. this research is an example of a census survey convenience sample simple random sample