how to set the answer up

Let s and g represents the numbers of suits and gowns produced.
The number of zippers used is 2s+g.
The number of buttons used is 5s+8g.
In order to use all of the available zippers and buttons, we must have ...
Cramer's rule tells you the solution to the system
Is given by
Using this rule on the equations for zippers and buttons, we have
... s = (1·576 -8·171)/(1·5 -8·2) = -792/-11 = 72
... g = (171·5 -2·576)/-11 = -297/-11 = 27
72 suits and 27 gowns can be made from available zippers and buttons.