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.
35
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