Pls pls pls help me. I cant solve it.

Which is equivalent to 450b^9 after it has been simplified completely

At a pizza shop 70% of the customers order a pizza 25% of the customers order a salad and 15% of the customers order both a pizza and a salad if s customer is chosen at random what is the probability that he or she orders either a pizza or a salad

Find y to the nearest hundreds place