SOLUTION: if you can buy b bananas for n nickels, how many bananas can you buy for d dimes and q quarters? - Here is what I tried: b=5n b=20n + 25q I thought this would be a system o

["b=5n" is wrong because you can't set bananas equal to money.]

Therefore b bananas sell for 5n cents

Divide the bananas and the money both by b:

Therefore  or 1 banana sells for  cents

Suppose the answer is x bananas:

Since one banana sells for  cents, 
x bananas sell for  cents.

Now we see how much money is d dimes and q quarters:

d dimes is 10d cents and q quarters is 25q cents
So d dimes and q quarters is 10d+25q cents.
We can factor out 5, 5(2d+5q)

Set that equal to 5(2d+5q)



Multiply both sides by b to clear of fractions:



Divide both sides by 5n



Cancel the 5's



That's the same as , choice (a)

Edwin