1.) (-18, -20) (18, 16) 2.) (-7, 14) (-11, 4)

3.) (-5, -4) (3, 9)

4.) (13, -8) (-9, -1)

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)