Your monthly car payment in dollars is p=f(p0,t, r), where $p0 is the amount you borrowed, t is the number of months it takes to pay off the loan, and r percent is the interest rate. (a) is ∂p/∂t positive or negative? what are the units of this value? (for this problem, write our your units in full, writing dollars for $, months for months, percent for %, etc. note that fractional units generally have a plural numerator and singular denominator.) (b) is ∂p/∂t positive or negative? what are the units of this value? (for this problem, write our your units in full, writing dollars for $, months for months, percent for %, etc. note that fractional units generally have a plural numerator and singular denominator.