Answer:
bat, $9.00; ball, $4.50
Step-by-step explanation:
Unit cost of bat (y) in terms of unit cost of ball (x)—2 equations combined:
4y + 9x - 3y - 12x = $76.50 - $81.00
y = 3x - $4.50
Price of a ball (x)—1st equation, substitute y:
4(3x - $4.50) + 9x = $76.50
12x - $18.00 + 9x = $76.50
21x = $94.50
x = $4.50
Cost of a bat—2 equations combined:
= 3($4.50) - $4.50
= $13.50 - $4.50
= $9.00