Respuesta :
{20a+15c=3550
{a+c=220
{20a+15c=3550
{15a+15c=3300
5a=250
a=50
There are 50 adult-size T-shirts were sold
{a+c=220
{20a+15c=3550
{15a+15c=3300
5a=250
a=50
There are 50 adult-size T-shirts were sold
Answer: There are 50 adult-size shirts that were sold .
Step-by-step explanation:
Since we have given that
Cost of adult-size shirts = $20
cost of child-size shirts =$15
Let hte number of adult-size shirt be x
Let the number of child-size shirt be y
According to question,
[tex]20x+15y=\$3550----------------------------(1)\\\\x+y=220---------------------------(2)\\\\[/tex]
So, we will use "Substitution method" :
[tex]x+y=220\\x=220-y[/tex]
Put this value in equation (1):
[tex]20x+15y=3550\\\\20(220-y)+15y=3550\\\\4400-20y+15y=3550\\\\4400-5y=3550\\\\4400-3550=5y\\\\850=5y\\\\\frac{850}{5}=y\\\\170=y[/tex]
So, put the value of y in x :
[tex]x=220-y\\\\x=220-170\\\\x=50[/tex]
Hence, there are 50 adult-size shirts that were sold .