Question 1133457
A box contains 65 coins, only dimes and nickels.
d + n = 65
or for substitution the form is
n = (65-d)
 The amount of money in the box is $5.40,
.10d + .05d = 5.40
replace n with (65-d)
.10d + .05(65-d) = 5.40
.10d + 3.25 - .05d = 5.40
.10d - .05d = 5.40 - 3.25
.05d = 2.15
d = 2.15/.05
d = 43 dimes
and
65 - 43 = 22 nickels
;
:
See if that checks out, find the actual amt of each
43(.10) = 4.30
22(.05) = 1.10
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Total $ = 5.40