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

5642 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

What is an inverse function?


There are 495 coins in a bottle. 1/3 of the coins are £1 coins. 124 of the coins are 50p coins. The rest of the coins are 20p coins. Work out the total value of the 495 coins


Natasha has two bags of fruit. both bags have the same number of fruit in total. 1/3rd of the fruit in bag 1 are apples and 15% of the fruit in bag 2 are apples. There are 20 apples in bag 1, how many apples are in bag 2?


In a class there are 57 students. Of these 32 study Spanish, 40 study German and 12 students study neither. How many students study Spanish but not German?


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