Set up two equations where d is the number of dimes and q is the number of quarters:

(1) d + q = 10

(2) 0.1d + 0.25q = 1.45

Rearrange (1) into (3) to solve for d

(3) d = 10 - q

Now plug (3) into (2)

0.1(10 - q) + 0.25q = 1.45

Multiply through:

1 - 0.1q + 0.25q = 1.45

Combine q terms

0.15q + 1 = 1.45

Subtract 1 from each side

0.15q = 0.45

Divide each side by 0.15

**q = 3**

Plug our q = 3 value into (3)

d = 10 - 3

**d = 7**