The graph of f(t) = 7.2 shows the value of a rare coin in year t. What is the meaning of the yintercept?
15
10-1
51
1
2
3
4
5

Suppose that the price p, in dollars, and the number of sales, x, of a certain item follow the equation 4 p plus 4 x plus 2 pxequals56. suppose also that p and x are both functions of time, measured in days. find the rate at which x is changing when xequals2, pequals6, and startfraction dp over dt endfraction equals1.5.