Let mA= 30°. If B is a supplement of A, and C is a complement of A, what is mB +mC?

This doesn’t make sense to me it’s supposed to be lcm ( least common multiple )

Which of the following is the correct ratio for converting kilograms to grams

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil