The rack of weight plated at the fitness center has a total of 148 plates weighing 2.5,5,and 10 pounds each. The total weight is 500 pounds. There are ten times as many 5 pound plates as 10 pound plates. Set up a matrix equations and then solve it to determine the number of each size of plate.

Thank you!!!

if there are x,y,z of each, in order, then

x+y+z = 148
2.5x + 5y + 10z = 500
y = 10z

Now you have your coefficients, so plug them into the matrix and find that

(x,y,z) = (104,40,4)