Answer:
X + 3y = 23
9x + 36y = 243
11 shirts sold at $9.0 per shirt, 4 shirts sold at $11 per shirt and 8 shirts sold at $12.5 per shirt
Step-by-step explanation:
-----Since we are told to assume that the number of shirts sold for $9.00 each is x, that of $11.00 is y and also that of $12.50 is z.
9x + 11y + 12.5z = 243
9x + 11y + 12.5(2y) = 243
9x + 36y = 243_______ equation 1
----- The statement also read that One day, the store sells a total of 23 shirts and makes $243 on the sales. TWICE AS MANY SHIRTS WERE SOLD FOR $12.50 THAN WERE SOLD FOR $11.00
Z = 2y
x + y + z = 23
X + y + 2y = 23
X + 3y = 23_____ equation 2
Now multiply the above by 9 to have this equation's "x" sharing the same coefficient with that of equation 1
9x + 27 = 207 will be the new one___equation 3
-----Subtract equation 3 from 1 and we have
9x + 36y = 243____ equation 1
9x + 27y = 207____ equation 3
9y = 36
Y = 4
-----Substitute y = 4 in equation 2
X + 3y = 23
X + 4(3) = 23
X + 12 = 23
X = 23 - 12
X = 11
-----Remember that x + y + z = 23
11 + 4 + z = 23
15 + z = 23
Z = 23 - 15
Z = 8.
So therefore, x =11 shirts, y = 4 shirts and z = 8 shirts
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