Question 69182
D+Q=15 D=15-Q NOW SUBSTITUTE (15-Q) FOR D IN THE SECOND EQUATION
10D+25Q=345
10(15-Q)+25Q=345
150-10Q+25Q=345
15Q=345-150
15Q=195
Q=195/15
Q=13 NUMBER OF QUARTERS.
D+13=15
D=15-13
D=2 NUMBER OF DIMES
PROOF
10*2+25*13=345
20+325=345
345=345