Answer:
see below
Step-by-step explanation:
vanilla = 4 dollars per packet
chocolate = 1 dollar per packet
v = number of vanilla packets
c = number of chocolate packets
v+c = 27 for a total of 27 packets
4v+1c = 45 for 45 dollars spent
Subtract the first equation from the second equation ( eliminate c to find v)
Since both equations have a coefficient of 1 for c, we can easily subtract to eliminate the c variable
4v + c =45
-v -c = -27
-------------------------
3v = 18
Divide by 3
3v/3 = 18/3
v = 6
6 packets of vanilla
Now find c
v+c = 27
6+c = 27
c = 27-6
c = 21
21 packets of chocolate