1 nickle = 5 cents = $0.05

1 dime = 10 cents = $0.1

let

n = the number of nickles

d = the number of dimes

tom has an equal number of dimes and nickels

d = n

he has $1.50 in all

0.05*n + 0.1*d = 1.50

by solving the system of equations

d = n

0.05*n + 0.1*d = 1.50

we find

d = 10 dimes

n = 10 nickles

Tom has 10 dimes and 10 nickles.