math
posted by hayden on .
box of chalk and 2 staplers cost $10.00. Three boxes of chalk and 2 staplers cost $18.00. How much is a box of chalk and a stapler?

x is box of chalk
y is staplers
x + 2y = 10
3x + 2y = 18
solve for x and then plug in and solve for y 
x+2y=10
3x+2y=18
Multiply the first equation by 1 to cancel the y's:
x2y=10
3x+2y=18
Now add the rows
2x=8
x=?
Now plug that back into either original equation to solve for y. 
16

the answer is