The owner of a guitar company plans to buy new materials for the manufacturing of guitars in three years at a cost of $25,000 she believes that she can earn 6% compounded semi annually find the amount of each of the semi annual payments needed

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180

the monthly balance will be $75,000

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72