Final answer:
The constraint equation for rexnorth blend requiring at most 25 pounds of coffee is xtr + xsr ≤ 25, where xtr and xsr are the coefficients.
Step-by-step explanation:
The constraint given is that rexnorth requires at most 25 pounds of coffee. Let's represent the pounds of typica coffee used in rexnorth blend as xtr and the pounds of sagada coffee used as xsr. So the constraint equation can be written as:
xtr + xsr ≤ 25
where xtr and xsr are the coefficients. The coefficient of xtr will be 1 and the coefficient of xsr will be also 1.