[tex]25:5=5\\5:5=1\\\\25=\boxed{5}\cdot5\\\\35:5=7\\7:7=1\\\\35=\boxed{5}\cdot7\\\\LCM(25,\ 35)=\boxed{5}\cdot5\cdot7=175[/tex]
Other method:
The multiples of 25: 0, 25, 50, 75, 100, 125, 150, 175, 200, ...
The multiples of 35: 0, 35, 70, 105, 140, 175, 210, ...
Answer: LCM(25, 35) = 175