Answer:
A packet of nuts costs $2.70
Explanation:
Let C represent the cost of a bar of chocolate and P represent the cost of a packet of nuts
4 bars of chocolate will cost $4C
1 packet of nuts costs $P
Total price Sandra paid is $11.50
This can be represented using
4C + P = 11.50 (1)
A bar of chocolate costs $0.50 less than a packet of nuts. So
P - C =0.50
-C + P = 0.50 (2)
Multiply eq (2) by 4 to get
-4C + 4P = 4 x 0.50
-4C + 4P = 2 (3)
Add equations (1) and (3) to eliminate the 4C term
4C + P - 4C + 4P = 11.50 + 2
P+4P = 13.50
5P = 13.50
Dividing by 5 on both sides
5P/5 = 13.50/5
P = 2.70
So a packet of nuts costs $2.70 (Answer)
To verify this is correct,
Use equation (2) to get
-C + P = 0.50
-C + 2.70 = 0.50
Add C to both sides
-C + 2.70 + C = 0.50 + C
2.70 = 0.50 + C
Subtract 0.50 from both sides
2.70-0.50 = 0.50 + C - 0.50
2.20 = C which is C= 2.20
Plug this value into equation (1)
4(2.20) + 2.70 = 8.80 + 2.70 = 11.50
So verified that answers are correct