Question

Brown rice costs $2 per pound and beans cost $1.60 per pound. Lin has $10 to spend on these items to make a large meal of beans and rice for a potluck dinner. Let b be the number of pounds of beans Lin buys and r be the number of pounds of rice she buys when she spends all her money on this meal.



a. Complete the equation relating the two variables.


r +
b =



b. Rearrange the equation so b is the independent variable.


= 5 – 0.8


c. Rearrange the equation so r is the independent variable.


= 6.25 – 1.25

Answer 1

2b + 1.6r = 10
infinite number of solutions

b = (10 - 1.6r)/2

r = (10 - 2b)/1.6

btw for a) if you really want just b + r

b + r = (10 - 1.6r)/2 + (10 - 2b)/1.6
= (16 - 2.56r + 20 - 4r)/3.2
= (36 - 6.56r)/3.2