one day a store sold 30 sweatshirts white ones cost 995 and

one day a store sold 30 sweatshirts. white ones cost $9.95, and yellow ones cost $10.50. in all, $310.60 worth of sweatshirts were sold. how many of each color were sold?

Solution

x + y = 30 The other equation will look like this:
9.95(x)+ 10.50(y) = 310.60 We can solve this by substitution. Make the first equation like this:
x=30-y Then we plug this into the second equation.
9.95(30-y)+10.50(y)= 310.60 Notice we have just y so we can solve this:
298.50-9.95y+10.50y = 310.60 Combine like terms.
298.50+.55y=310.60 Subtract 298.50 from both sides.
.55y=12.10 Divide each side by .55
y=22