How can you expand brackets? e.g: (x-4)(x+7)

The answer is of the form ax2+bx+c The a term is found by the product of the coefficients of the x in the brackets. e.g (2x+7)(-4x+6) would give -8x2 . However for this example, we will only use coefficients of 1. The coefficient of the x term (b) will be sum of the numbers after the x (e.g: (6x-4)(4x+3)). For the first bracket the b term is -4 and for the second bracket the b term is +3. The product of these numbers is -1, so this is the coefficient of the x term. The c term in the quadratic is the product of these numbers. Using the previous example, -4 x 3 = -12 so this is the c term. Putting these answers into our quadratic give us x2+3x-28.

Answered by Sam T. Maths tutor

4619 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A t-shirt is in the sale section of a store. It has 20% off and the new sale price is £12. What was the original price of the t-shirt?


What is the range of the function y = x^2?


Complete the square for the equation x^2 - 12x + 8 = 0


The formula for finding the circumference of a circle is Equation: C = 2(pi)r . What can we do if we know the circumference but want to know the radius?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences