Question 483205
let x = no. of dimes (1 dime = 10 cents)
    y = no. of quarters (1 quarter = 25 cents)

x + y = 22 coins
x = 22 - y      (eq. 1)

0.1x + 0.25y = 4.75  (eq. 2)

SUBSTITUTE eq. 1 to eq. 2
0.1(22 - y) + 0.25y = 4.75
2.2 - 0.1y + 0.25y = 4.75
-0.1y + 0.25y = 4.75 - 2.2
0.15y = 2.55
y = 17 total number of quarters

x = 22 - y
x = 22 - 17
x = 5 total number of dimes