Can you please help 7-9 and explain all. I’m having trouble understanding.

Use the inverse of the function y=x^2-18x to find the unknown value [tex]y = \sqrt{bx + c \: + d} [/tex]

If t8 = 4 and t12 = −2, find the first three terms of the arithmetic sequence.

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