http://www.emaths.co.uk/sats/2009/2009_68_Paper1.pdf
please go to question 24 and help me answer
http://www.emaths.co.uk/sats/2009/2009_68_Paper1.pdf
please go to question 24 and help me answer
This looks a lot like a test, so here is just a hint:
Notice they have told you the two equations you need to deal with. You have 2 variables and 2 equations. Do you know how to solve simultaneous equations? When you solve for x and y, make sure you pair up the right numbers with each other for the 2 points.
Feel free to ask if you need any more help.
The information tells you that at the points A and B, [b]both[/both] the equations and are correct for the same x and y values.
So, to solve for the intercepts, you need to simultaneously solve the equations
and .
You know that , so anywhere you see a , you are allowed to substitute it for because they are both the same thing. (Think of it like if you know , you can put wherever you see a .
Well, you see a in the second equation; you can substitute that for something else that equals it: .
This gives you:
and
to find the y value for these points simply plug them into one of the original equations:
These give you the points (0,-2) and (1,-1).
Since you can see on the graph that point A lies on the y-axis (where x is always 0), you know that point A is (0,-2) and point B has to therefore be (1,-1).
Hope that helps