Question 347692
Word Problem: The senior class is selling greeting cards. 
Birthday Cards sell for $5.00 a box. 
Thank You cards sell for $7.00 a box. 
You sold 4 more boxes of birthday cards than thank you cards. 
your total sales was $152.00. 
How many Boxes of each kind did you sell?
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Equations:
Quantity Eq.:: b = t+4
Value Eq.:::: 5b + 7t = 152
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Rearrange for Matrix:
b  - t  = 4
5b +7t  = 152
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Using a Matrix Method I get:
b = 15 (# of birthday card boxes sold)
t = 11 (# of thankyou card boxes sold)
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Cheers,
Stan H.