To find a fraction equivalent to 3/7 you just multiply the numerator (top number of fraction) and the denominator (bottom number of fraction) by the same number (i.e. 2/2, 5/5, etc.)
3/7 * 2/2 = 6/14
3/7 * 3/3 = 9/21
3/7 * 4/4 = 12/28
3/7 * 5/5 = 15/35
3/7 * 6/6 = 18/42
3/7 * 7/7 = 21/49
3/7 * 8/8 = 24/56
3/7 * 9/9 = 27/63
3/7 * 10/10 = 30/70
All of those are equivalent to the fraction of 3/7.
I hope you got a good grade on your assignment!!! :D