At what point(s) do lines y = x^2 - 5x - 14 and y = 3x + 2 intersect? Write your answer in surd form

To find the point(s) where these two lines intersect we will first find the x coordinate of the point(s) where they intersect snd use this to find the corresponding y coordinate by substituting the x value into one of the linear equations. To find the x value(s) we can use the fact that y = y, so we can write x2-5x-14 = 3x+2 since x2-5x-14 = y and 3x+2 = y. We can rearrange this to get x2-8x-16=0 which is a quadratic equation, meaning we can use the quadratic formula to find our x value(s).
You should find that there are two x values, x = 4 + 4(sqrt(2)) and x = 4 - 4(sqrt(2)) (sqrt(2) is square root 2!)We can now use these x values to find their corresponding y values simply by substituting them into y = 3x + 2.Doing this we find that the points where the two lines intersect are (4 + 4(sqrt(2)), 14 + 12(sqrt(2))) and (4 - 4(sqrt(2)), 14 - 12(sqrt(2))). To double check your values try substituting your x values into the other linear equation and see if they give you the same answer!

KJ
Answered by Kieran J. Maths tutor

4289 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What are the roots of y=x^2+5x+6 ?


f(x) = x^3 + 3x^2 + 5. Find (a) f ′′(x), (b) ∫f(x)dx.


A curve has equation y = (x-1)e^(-3x). The curve has a stationary point M. Show that the x-coordinate of M is 4/3.


Show that the equation 2sin^2(x) + 3sin(x) = 2cos(2x) + 3 can be written as 6sin^2(x)+3sin(x) - 5 = 0. Hence solve for 0 < x < 360 degrees. Giving your answers to 1.d.p.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning