Question 326894
Let D be the number of dimes, Q quarters.
Total number of coins:
1.{{{D+Q=46}}}
Total value of coins:
{{{10D+25Q=700}}}
2.{{{2D+5Q=140}}}
From eq. 1,
{{{D=46-Q}}}
Substitute in eq. 2,
{{{2(46-Q)+5Q=140}}}
{{{92-2Q+5Q=140}}}
{{{3Q=48}}}
{{{highlight(Q=16)}}}
Then,
{{{D=46-Q}}}
{{{highlight(D=30)}}}