Answer:
The store should use 112.5 pounds of Brazilian coffee and 37.5 pounds of Colombian cofee.
Step-by-step explanation:
Let "b" be the amount of Brazilian coffee, in pounds, required for the blend and "c" the amount of Colombian coffee required, in pounds.
Since there are two unknown variables a two-equation system is needed to solve the problem, we can set up one equation for weight and another for price as follows:
Solve for "c" by multiplying the first equation by -10 and adding it to the second one:
Now, solve for b by replacing the value obtained into the first equation
The store should use 112.5 pounds of Brazilian coffee and 37.5 pounds of Colombian cofee.