Question 344080
1.{{{N+D+Q=30}}}
2.{{{D=2N}}}
3.{{{5N+10D+25Q=550}}}
Substitute eq. 2 into eq. 1 and eq. 3.
{{{N+2N+Q=30}}}
4.{{{3N+Q=30}}}
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{{{5N+10(2N)+25Q=550}}}
{{{5N+20N+25Q=550}}}
{{{25N+25Q=550}}}
5.{{{N+Q=22}}}
From eq. 4,
{{{2N+(N+Q)=30}}}
Substitute from eq. 5,
{{{2N+22=30}}}
{{{2N=8}}}
{{{highlight(N=4)}}}
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{{{D=2N}}}
{{{D=2(4)}}}
{{{highlight(D=8)}}}
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Then from eq. 1,
{{{4+8+Q=30}}}
{{{highlight(Q=18)}}}