Greg's Coffee Shop makes a blend that is a mixture of coffee types A and B. In one bag of the blend, there are 3 kilograms of type A. Seven bags of the blend are a total of 63 kilograms. How many kilograms of type B are there in one bag? (a) Write an equation that could be used to answer the question above. First, choose the appropriate form. Then, fill in the blanks with the numbers 3, 7, and 63. Let b represent the number of kilograms of type B in one bag.

° [] (b + []) = []

° [] (b - []) = []

Please answer those two and tell me which answer choice.

(b) Solve the equation in part (a) to find the number of kilograms of type B in one bag.

b = []​

PLEASE HURRY AND HELP ME! ITS DUE IN A COUPLE OF HOURS!