Answer:
The number of dimes she has = 42
Explanation:
Rhianna has $5.25 in dimes and nickels for a total of 63 coins.
Let the number of nickels be x and the dimes be y.
Since nickels = 0.05 cent and Dimes = 0.10 cent
Now we will form the equations.
10 y + .05 x = 5.25
5x + 10y = 525
x + 2y = 105 ------(1)
x + y = 63 ----(2)
By subtracting equation 2 from 1.
(x + 2y)-(x + y) = 105 - 63
x + 2y - x - y = 42
y = 42
By putting y = 42 in equation 1
x + 42 = 63
x = 63 - 42 = 21
Therefore
Number of dimes will be 42.