1) 153/1960=(3*17*3)/(8*5*7*7)
867/17150=(3*17*17)/(5*5*7*7*7*2)
((3*17*3)/(8*5*7*7)):((3*17*17)/(5*5*7*7*7*2))=((3*17*3)/(3*17*17))*((5*5*7*7*7*2)/(8*5*7*7))=(3/17)*((5*7)/4)=105/68
2) 1176/350=(3*2*2*2*7*7)/(5*5*2*7)
1925/756=(11*5*5*7)/(2*2*3*3*3*7)
((3*2*2*2*7*7)/(5*5*2*7))*((11*5*5*7)/(2*2*3*3*3*7))=((3*2*2*7)/(5*5))*((11*5*5)/(2*2*3*3*3))=((3*2*2*7)/(2*2*3*3*3))*((11*5*5)/(5*5))=(7/9)*11=77/9