If we assume the number of polo shirts have been sold is x, the number of casual shirts have been sold will be 4x.
x*18+4x*9=$1080
(18+36)x=$1080
54x=$1080
x=20
The number of casual shirts have been sold is 4*20=80
To Find :
How many gallons of a 80% antifreeze solution must be mixed with 100 gallons of 20% antifreeze to get a mixture that is 70% antifreeze.
Solution :
Let, x gallons of 80% antifreeze solution is required :
So,

Therefore, 500 gallons of 80% antifreeze solution is required.
<span>(x/y)+(3/y)=(x+3)/y
the answer is
the numerator for the following rational expression</span> is x+3
Try this suggested option, answers are marked with colour.