Answer:
500 and 900
Explanation:
3(x - 300) + 2(x + 100) = 3300 ← distribute parenthesis
3x - 900 + 2x + 200 = 3300
5x - 700 = 3300 ( add 700 to both sides )
5x = 4000 ( divide both sides by 5 )
x = 800
Then
cost of book = x - 300 = 800 - 300 = 500
cost of pen = x + 100 = 800 + 100 = 900