Question

Draw the graph of each pair of linear equations below using the same Cartesian plane.
1. 3x + y =5 and 2x + y =9

Answer 1

Well first you would want to make y the subject of these to make it easier to draw a graph...

Answer 2

Then?

Answer 3

Do you know how to draw graphs?

Answer 4

A liitle bit

Answer 5

How much do you know? Do you know which part of the y= equation is the slope/gradient of the line and which part is the y intercept?

Answer 6

yes

Answer 7

Well then, for both lines you have the gradient and the y intercept... so it shouldn't be too hard to draw the lines with these

Answer 8

But, how could I graph this , through what type of plotting points??

Answer 9

I might have learnt a different method of graphing at my school than yours, but we learnt that the coefficient of x is the gradient (ie the slope, how many units it goes upwards for every unit it goes along) and the + or - number after the x value is where it intercepts the y axis.. if that makes sense

Answer 10

Not quite... You have 2 equations, so you will have two different lines.

Answer 11

Can you give example?

Answer 12

so one of your equations is 3x+y=5...
that will rearrange to y = -3x + 5, right?

Answer 13

Yes

Answer 14

So -3 will be the slope of line as it's the coefficient of x; ie for every 1 unit along, the line will go down 3 units. And the +5 means it cuts through the y axis at y=5. Does this make any sense?

Answer 15

(please excuse the poorly drawn freehand line)

Answer 16

How about 2x + y =9?

Answer 17

Well, first rearrange that for y and then draw the line...
I think I should let you try this one for yourself :P

Answer 18

Ok thank you, so this is my last question:
Determine the solution set of the system of linear equation as shownby the graph:

Answer 19

The solution set is the coordinate on the graph where the two lines intercept.