Coffee cafe makes 90 pounds of coffee that costs $6 per pound. the types of coffee used to make this mixture cost $7 per pound and $4 per pound. how many pounds of $7-per-pound coffee should be used in this mixture?

the answer is 60 lbs of $7/lb coffee is needed in this mixture.

Step-by-step explanation:

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

∠cbe and ∠deb are same-side interior angles.

i took the test