Answer:
pizza: $4, coke: $3, chips: $2
Step-by-step explanation:
Lets make the price of a pizza=p a coke= k and a bag of chips=c
then we have the following equations
p+k+c=9
p+2k=10
2p+2c=12
Because p is common in all the equations we shall make it the subject of each equation.
p=9-(k+c)...........i
p=10-2k..............ii
p=6-c...................iii
We then equate i and iii
9-(k+c)=6-c
9-k-c=6-c
putting like terms together we get:
9-6=-c+c+k
1 coke, k=$3
replacing this value in equation ii
we get p=10-2(3)
p=10-6= 4
1 pizza, p=$4
replacing this value in equation iii
4=6-c
c=6-4
=2
a bag of chips, c=$2
Thus, a pizza, a coke and a bag of chips= pizza: $4, coke: $3, chips: $2