What type of angle is formed where a line of latitude and a line of longitude cross?

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Will mark 50 show all what is the solution to the system of equations? use the substitution method and show your work. -5x+y= -3 -15 x+3y=7 explain what your answer in part (a) tells you about the association of the lines in this system.