0.004 X 100 = 0.004 X 102

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

Can someone tell me if this is perpendicular? !