Lets calculate gear ration T2/T1
so the gear ratio will be 1.6 it simply means dat if u rotate large gears one full revolution it tends to turn another short wheel to 1.6 revs, so in ur qtion the large whell revs 100 den u must multiply wid 1.6*100= 160 revs
A line that is parallel to x=0 has to be x=k where k is a constant. In (4,2), x=4. Therefore, the answer is x=4.
