Can anyone give me a hint or answer this?

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.

Given lm, find the measure of (award brainliest)

Miguel has 334 baseball cards and 278 football cards. he says, i have 612 cards in all. is that reasonable? explain using the words round and estimate.