6s+4d=$53
4s+6d=$47
Multiply 6 in the first equation which is
36s+24d=$318
Multiply -4 in the second equation which is
-16s-24d=$-188
Then..
36s+24d=$318
-16s-24d=$-188
You cancel out the -24d and +24d
36s=$318
-16s=$-188
Do the math..
20s=$130
Divide 20 by both sides and answer...
s=$6.5
