Question 914852: Two similar books and 3 similar pens cost $55. 4 such books and 5 such pens cost $97. Find the cost of each book. Answer by mananth(16946) (Show Source):
4 x + 5 y = 97 .............2
Eliminate y
multiply (1)by -5
Multiply (2) by 3
-10 x -15 y = -275
12 x + 15 y = 291
Add the two equations
2 x = 16
/ 2
x = 8
plug value of x in (1)
2 x + 3 y = 55
16 + 3 y = 55
3 y = 55 -16
3 y = 39
y = 13 1
x= $8 cost of book
y= $13 cost of pen
m.ananth@hotmail.ca