Matricess

[sandi]

Juni is attempting to determine the best number of each type of printer ink to buy. Black cartrirdges cost $50 each while the cyan and yellow cartridges cost $40 eahc. Magenta cartidges cost $45 each. THe following informations is known:
 
The total money available to buy all the catridges is $375
The number of black cartridges required will be equal to the number of other(coloured) cartridges.
A total of 16 cartridges are to be purchased
The number of yellow required is 50% more than the number of cyan.

a)Write down a matrix equation incorporating this information.

[fred42]

Please check the question again. There appears to be something wrong as the answer gives a negative value for the number of cartridges of magenta.