Given :
The cost of 3 shirts and 5 sweaters is $99 .
The cost of 6 shirts and 4 sweaters is $90.
To determine :
The sweater cost and shirt cost each.
Explanation :
Let the shirt cost be x.
Let the sweater cost be y.
Then the equation formed is
[tex]3x+5y=99\ldots\ldots\ldots\ldots\ldots\ldots..1[/tex][tex]6x+4y=90\ldots\ldots\ldots\ldots\ldots\ldots\ldots\ldots2[/tex]Solve the equation 1 and 2 to find x and y with the help of elimination method.
Multiply by 2 in equation 1.
[tex]6x+10y=198\ldots\ldots\ldots\ldots\ldots\ldots.\ldots.\ldots3[/tex]Solve equation 2 and 3 by subtraction,
[tex](6x+10y-198)-(6x+4y-90)=0[/tex][tex]6y-198+90=0[/tex][tex]6y=108[/tex][tex]y=18[/tex]The value of y is 18 and now substitute the value of y in equation 2 to find x.
[tex]6x+4y=90[/tex][tex]6x+4\times18=90[/tex][tex]6x=90-72[/tex][tex]6x=18\Rightarrow x=3[/tex]The value of x is 3.
Answer :
The cost of shirt is 3 dollar .
The cost of sweater is 18 dollar.
