4.

 Solve the following equations, giving your answers correct to two decimal places,

 where necessary.

 

 

5.

 The diagram shows a triangle ABC, where AB = x cm and CD, is 3 cm shorter that

 AB.

 (a) Form an equation in terms of x that represents the area of the triangle,

 (b) If the area is 72 cm², find the value of x, giving the answer correct to two decimal places.