Then the original price was $42
Because it is half off we multiply 21 by 2 and get 42.
Let the cost of 1 notebook be x and the cost of 1 binder be y.
4 notebooks and 3 binders would cost 23.5
Therefore, 4x + 3y = 23.5 (1)
7 notebooks and 6 binders would cost 44.5
Therefore, 7x + 6y = 44.5 (2)
Multiply the first equation by 2.
8x + 6y = 47 (3)
(3) - (2) gives
x = 2.5
Substitute the value of x in (1), we get,
4(2.5) + 3y = 23.5
10 + 3y = 23.5
3y = 23.5 - 10
3y = 13.5
y = 13.5/3
y = 4.5
Hence, cost of 5 notebooks and 3 binders is:
5x + 3y = 5(2.5) + 3(4.5)
= 12.5 + 13.5
= 26
Hence, cost of 5 notebooks and 3 binders is $26.
how many solutions do intersecting lines have? - 0,1 or infinitely many
how many solutions do parallel lines have? - 0 or infinitely many
if you are looking at a graph and trying to find a solution what are you looking for? - for the point(s) when the graphs intersect
