35
Least common denominator of 7 and 5 is 35.
The Least Common Denominator of 5, 7, and 35 is 1.
The least common denominator is 280.
The least common denominator (LCD) is 630.
The least common denominator of 2, 5 and 7 is 70. Since all those numbers are prime, the answer is their product.
315.
105
140
The least common denominator is 28.
420
210
63