Answer:
1. For buying 4 pencils and 2 pens we pay 5600 L.L. and for buying 2 pencils and 3 pens we pay 7800 L.L.
2. The price of one pencil is 150 L.L. and the price of one pen is 2,500 L.L
Step-by-step explanation:
The given system of equation are;
4·x + 2·y = 5,600...(1)
2·x + 3·y = 7,800...(2)
Where x represent the price of one pencil and y represents the price of one pen
Therefore, we have;
1. For buying 4 pencils and 2 pens we pay 5600 L.L. and for buying 2 pencils and 3 pens we pay 7800 L.L.
2. By making y the subject of both equations we have;
For equation (1)
y = 5,600/2 - 4·x/2 = 2,800 - 2·x
y = 2,800 - 2·x
For equation (2)
y = 7,800/3 - 2·x/3 = 2,600 - 2·x/3
y = 2,600 - 2·x/3
Equating both values of y gives;
2,800 - 2·x = 2,600 - 2·x/3
2,800 - 2,600 = 2·x - 2·x/3
200 = 4·x/3
600 = 4·x
x = 600/4 = 150
∴ The price of one pencil = 150 L.L.
y = 2,800 - 2·x = 2,800 - 2 × 150 = 2,500
∴ The price of one pen = y = 2,500 L.L.
