the first fraction is 4 over 6, right? hopefully it is, i cant really see.
Basically, you can divide 4 and 6 by the same number, they have factors in common. They're both multiples of 2. if you divide them both by 2, you get 2 over 3, which is the exact same amount as 4 over 6, it's just written in a simpler way. the first answer is 2 over 3.
What numbers can both 10 and 15 be divided by? give it a try.