Quadratic Formula

This item is taken from IGCSE Mathematics (0580) Paper 43 of October/November 2010.

To deal with this item, let us summarize the details of the problem:
   (a) Syllabus area: Algebra
   (b) Specific topic: The Quadratic Formula
   (c) Formula Needed:

Let us take note that the given is a quadratic equation but it is not factorable. We can then find the solution(s) of the equation by using the quadratic formula.

Let us first identify the values of a, b and c for the quadratic formula.

We can now substitute the values of a, b and c in the formula:

At this point, we should not get the decimal value first of the square root of 17. Leave it as is. 

We can now separate the solution into two, separating the "+"and "-" signs, then simplify.

Therefore, the solutions for the equation is x = -0.22 or x = -2.28.

*We should take note also that the complete working is required in this item. The most important part of it is the correct quadratic formula with correct values of a, b and c.

-------------------------------------------------------------------------------------------------------------- 
Your comments and suggestions are welcome here. Write them in the comment box below.

Thank you and God bless!