If b = the number of blue bikes, which algebraic expression represent the phrase below? the sum of the number of blue bikes and the 9 red bikes

The answer would be the algebraic expression, b + 9. The translation here is b is representing the number of blue bikes then you needed to add the 9 which represents the 9 red bikes. The two is added together, to get the total of those red and blue bikes which we are looking for.