Question 660243
x = quarters
y = nickels
z = dimes

x + y + z = 14
y = 5 nickels
z = y + 1

Substitute the second equation into the third
z = y + 1 = 5 + 1 = 6 dimes
Substitute the second and third equations into the first
x + 5 + 5 + 1 = 14
Isolate x
x + 11 = 14
x + 11 - 11 = 14 - 11
x = 3 quarters