It would be 40 because 10 can be multiplied by 4 to get 40 and 40 can be mulitiplied by 1 to get 40. Don't forget to mulitply the numerators by the same number, too.
A common denominator, though not the least, is 40.
40
It is: 40
The least common denominator (LCD) is 40.
The LCD is 40.
A common denominator, though not the least, is 40.
40
40
40
40
It is: 40
The least common denominator (LCD) is 40.
The LCD is 40.
120
40
It is 80
200