you first have 52. Well they take 2 out. Which equals to 50. So does that mean you have to dvide.

a card is selected at a random from a standard deck of 52 cards. Than a second card is selected without replacing the first card.

find the probabilitiy of selecting two red cards.

please help me

Where do you think you should start?
Are all the cards the same color?

well the probability of selecting the first red card is 26/52,
and the probability of selecting the second red card is 25/51.

What's the probability of doing both?

For the first draw, as there are 26 cards of each colour in the pack then the probability is 26/52 or 0.5. I'll leave you to work out the second...