Which is a common denominator of 1 /4 and 3/ 5
Please help

1/4 and 3/5So 20 is a common denominator

20

Step-by-step explanation:

Common denominator is just LCM

1.

a. Perimeter of the Picture would be all the sides added up all together. Since it's a 5in. by 7in. picture we know that two sides equal 5 inches and the other two sides equal 7 inches.
5+5+7+7=
10+14=
24 inches

b. If I'm understanding correctly then ...
There is a 1 inch between the picture and the frame.
Thus, each side of the picture has two added inches (one inch on the right and left side)

So, the sides with 5 inches now have two inches extra resulting in its length becoming 7 because 5+2=7
The other two sides with 7 inches now have two extra inches as well. Now becoming nine inches in length.

The frame is determined to be a 7in. by 9in.
Just like we did with the picture, we know add up all the sides.
7+7+9+9=
14+18=
32inches

Hope I didn't mess up for your sake!