Question
Postcard stamps are 20¢ each, while letter stamps are 33e each. If you have 50 stamps worth $12.60, how many of each type do you have?
How to set this as a matrix equation?
How to set this as a matrix equation?
Answers
oobleck
P+L=50
20P+35L = 1260
(1 1)(P) ......(50)
(20 33)(L) = (1260)
for a more readable version, see
https://www.wolframalpha.com/input/?i=%7B%7B1%2C1%7D%2C%7B20%2C33%7D%7D+*+%7B%7BP%7D%2C%7BL%7D%7D+%3D+%7B%7B50%7D%2C%7B1260%7D%7D
20P+35L = 1260
(1 1)(P) ......(50)
(20 33)(L) = (1260)
for a more readable version, see
https://www.wolframalpha.com/input/?i=%7B%7B1%2C1%7D%2C%7B20%2C33%7D%7D+*+%7B%7BP%7D%2C%7BL%7D%7D+%3D+%7B%7B50%7D%2C%7B1260%7D%7D