Question 804342
x=nickels y=dimes
nickels plus the dimes is equal to 63 coins total.
x+y=63
nickels are .05 and dimes are .10.  The total amount you have is $4.00.
.05x+.10y=4
to solve for nickels, solve x+y=63 for y
y=63-x
now plug into .05x+.10y=4
.05x+.10(63-x)=4
.05x+6.3-.10x=4
-.05x=-2.3
x=46
You now know you 46 of the 63 coins are nickels.
63-46=17
The answer is 46 nickels and 17 dimes.