Answer:
The store sold 1 white sweatshirt and 20 yellow sweatshirts
Step-by-step explanation:
Step 1: Express total cost of sweatshirts
Total cost of sweatshirts can be expressed as;
Total cost=(price per white sweatshirt×number of white sweatshirts sold)+(price per yellow sweatshirt×number of yellow sweatshirt sold )
where;
Total cost=$260.95
Price per white sweatshirt=$10.95
number of white sweatshirts sold=w
Price per yellow sweatshirt=$12.50
number of yellow sweatshirt sold=y
Replacing;
260.95=(10.95×w)+(12.5×y)
10.95 w+12.5 y=260.95...equation 1
Step 2: Express total number of sweat shirts sold
Total number of sweatshirts sold=number of white sweatshirts sold+number of yellow sweatshirt sold
where;
Total number of sweatshirts sold=21
number of white sweatshirts sold=w
number of yellow sweatshirt sold=y
replacing;
w+y=21...equation 2
Step 3: Solve simultaneously equation 1 and 2
1(10.95 w+12.5 y=260.95)>>>10.95 w+12.5 y=260.95
-
12.5(w+y=21)>>>12.5 w+12.5 y=262.5
(10.95 w-12.5 w)+(12.5 y-12.5 y)=260.95-262.50
-1.55 w=-1.55
w=1.55/1.55
w=1
Replace the value of w in equation 2
w+y=21
1+y=21
y=21-1=20
The store sold 1 white sweatshirt and 20 yellow sweatshirts
