What is the literal equations for v=lwh what is w

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 (%)

Write a linear funtion f with the values f(2)=-1, and f(5)=4

If f(x)=x^2- 4 and g(x)=x^2 plus 2 x, (c) (f-/3) = ? (simplify your answer.)