Question 163623
Nadine has seven more nickels than Delano has dimes. If Delano gives Nadine four of his dimes, then Delano will have the same amount of money as Nadine. How much money do they have together? (Assume that Nadine has only nickels and Delano has only dimes.
:
Let x = no. of  N's nickels
Let y = no. of D's dimes
:
"Nadine has seven more nickels than Delano has dimes."
x = y + 7
:
"If Delano gives Nadine four of his dimes, then Delano will have the same amount of money as Nadine."
.05x + .10(4) = .10(y-4)
.05x + .40 = .10y - .40
.05x = .10y - .40 - .40
.05x = .10y - .80
Substitute (y+7) for x
.05(y+7) = .10y - .80 
.05y + .35 = .10y - .80
.35 + .80 = .10y - .05y
1.15 = .05y
y = {{{1.15/.05}}}
y = 23 dimes
and
x = 23 + 7 = 30 nickels
:
Check for equality
.05(30) + 4(.10) = .10(23-4)
1.50 + .40 = .10(19)
:
 How much money do they have together? 
23(.10) + 30(.05) = 
2.30 + 1.50 = $3.80