Simultaneous equationsAQA A-Level Maths: Flashcards

What these 13 flashcards ask

What are simultaneous equations?
When should you use elimination?
When do you add the equations to eliminate a variable?
When must you use substitution?
Solve x+2y=7 and 3x-y=7.
What should you do after finding x from a line and a curve?
Expand (k-2x)^2.
A line meets a curve at two points. What is the sign of the discriminant?
What does b^2-4ac=0 tell you after substitution?
What does b^2-4ac<0 tell you after substitution?
Rectangle: perimeter 34, diagonal 13. Write the equations.
How do you check a solution?
Give the distance between (3,4) and (-2,-1).

Exam questions on Simultaneous equations

The straight lines $x+2y=7$ and $3x-y=7$ meet at the point $P$ . The first line crosses the $y$ -axis at $A$ and the second line crosses the $y$ -axis at $B$ .
Find the area of triangle $ABP$ .2 marks
The line $y=x+1$ and the curve $y=x^{2}-5$ intersect at two points.
Find the exact distance between the two points of intersection.2 marks
The line $2x+y=k$ , where $k$ is a constant, and the curve $C$ with equation $x^{2}+y^{2}=20$ .
Show that the $x$ -coordinates of any points of intersection satisfy $5x^2-4kx+k^2-20=0$ .3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).