Question 157310
(1){{{q + d + n = 197}}}
(2){{{d = (1/3)*n + 2}}}
(3){{{q = 3d}}}
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(1) and (3) substitution
(4) {{{3d + d + n = 197}}}
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(2){{{d = (1/3)*n + 2}}}
{{{3d = n + 6}}}
{{{n = 3d - 6}}}
substitute this in (4)
{{{3d + d + 3d - 6 = 197}}}
{{{7d = 203}}}
{{{d = 29}}}
There are 29 dimes
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check:
(3){{{q = 3d}}}
{{{q = 3*29}}}
{{{q = 87}}}
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{{{n = 3d - 6}}}
{{{n = 3*29 - 6}}}
{{{n = 81}}}
{{{q + d + n = 197}}}
{{{87 + 29 + 81 = 197}}}
{{{197 = 197}}}
OK