Solve the following quadratic simultaneous equation: y = x + 4 and y = x^2 + 4x

Y = x + 4y = x2 + 4x(as both are equal to y, they can be equated)So: x2 + 4x = x + 4(Rearrange to make the equation equal 0 - subtract x and 4)x2 + 3x - 4 = 0(factorise)(x + 4)(x - 1) = 0Therefore: x = -4 or x = 1(plug these values back into the original equation to find the corresponding values of y)If x = -4, y = - 4 + 4So y = 0If x = 1, y = 1 + 4So y = 5 This means the solutions to these equations are:x = -4 and y = 0x = 1 and y = 5

JC
Answered by Julius C. Maths tutor

5588 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

The distance from the Earth to the Sun is 93 million miles. Assume: it takes 365 days for the Earth to travel once around the Sun and the Earth travels in a circle with the Sun at the centre. Work out the average speed of the Earth in miles per hour.


What is completing the square and how do I do it?


How do you calculate the area of a circle?


How do I graph linear inequalities?


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences