What is the expansion of (x + 4)(x - 5) ?

To expand this we multiply the first term in each bracket together to get x2 Then we do the first bracket's first term by the second bracket's second term to get -5x The we do the first bracket's second term by the first, then the second, terms of the second bracket to get 4x -20 Together that makes x2 - 5x + 4x - 20 and we can simplify this to get x2 - x + 20 which is the answerTo remember how to expand you can use the acronym FOIL, multiplying the First, Outside, Inside, Last terms together before simplifying.

HD

Related Maths GCSE answers

All answers ▸

P is a point on a circle with the equation x^2 + y^2 = 45. P has x-coordinate 3 and is above the x axis. Work out the equation of the tangent to the circle at point P.


In a triangle ABC where angle CAB = 90 and angle ABC = 40 and the hypotenuse = 20cm, what is the length CA? Then find the total perimeter of the triangle.


How do I solve a quadratic equation by completing the square?


I am getting stuck on how to solve Simultaneous Equations, can you explain how to do this?