The equations that you would use is 14x+6x+16x=326, where x is equal to the number of instruments sold. If you plug in the 12 sets of maracas, the 5 sets of claves and x djember drums and multiply by the prices for each instruments, you should be able to find your answer. Your answer should be you sold 8 djembe drums. Using the information i provided to you plug the numbers in and see if your answer matches up with mine. let me know if you have any further questions.