slope = rise over run = y/x
A (-1,3) slope = 3/-1 = -3
B (1,2) slope = 2/1 = 2
C (-3,-1) slope = -1/-3 = 1/3
2 lines need to be negative reciprocals in order to be a right triangle
negative reciprocal of -3 is 1/3
so this is a right triangle
One scarf=s
One hat=h
2s+h=13
s+2h=14
h=13-2s
(plug that into the other equation)
s+2(13-2s)=14
s+26-4s=14
26-3s=14
-3s=-12
s=4
One hat=$5
One scarf=$4
5+4=9
Price of one hat AND one scarf is $9
Hello!
I just completed this test and if I'm correct in assuming that this is the same problem I did, then your answer would be 18 cm.
Hope this helps! :)
