Answer:
Smaller coin = s = $0.25 = 25cent.
larger coin = l = $0.5 = 50 cent
Explanation:
Given the following :
Let the two coins be s and l
Where s = smaller denomination and l = larger denomination coins
Two of the smaller denomination coins and three of the larger denomination coins have a value of $2
2s + 3l = 2 - - - - (1)
Two of the smaller denomination coins and seven of the larger denomination coins have a value of $4
2s + 7l = 4 - - - (2)
2s + 3l = 2 - - - (1)
2s + 7l = 4 - - - (2)
Subtracting both equations
3l - 7l = 2 - 4
-4l = - 2
l = 2/4
l = 0.5
Put l = 0.5 into (1)
2s + 3l = 2
2s + 3(0.5) = 2
2s + 1.5 = 2
2s = 2 - 1.5
2s = 0.5
s = 0.5 / 2
s = 0.25
Smaller coin = s = $0.25 = 25cent.
larger coin = l = $0.5 = 50 cent