Answer:
Cost of first pair shoe = a = $23
Cost of second pair shoe = b = $46
Cost of third pair shoe = c = $28
Explanation:
Let
Cost of first pair shoe = a
Cost of second pair shoe = b
Cost of third pair shoe = c
The first pair of shoes were not too expensive, but the second pair was twice as much as the first pair.
b = 2a......... Equation 1
The third pair of shoes were $5 more than the first pair.
c = a + 5...... Equation 2
She paid with a $100 bill and got $3 in change.
a + b + c = $100 - $3
a + b + c = 97........... Equation 3
Substitute 2a for b and a + 5 for c in Equation 3
a + 2a + a + 5 = 97
4a = 97 - 5
4a = 92
a = 92/4
a =$23
The cost of the first pair of shoe = $23
b = 2a......... Equation 1
b = 2($23)
b = $46
The cost of the second pair of shoe = $46
c = a + 5...... Equation 2
c = $23 +$5
c = $28
The cost of the third pair of shoe = $28