Question

Solve the following simultaneous equations graphically.
x + y = 5; x – y = 3

Answer 1

x + y = 5 ....(1)

x – y = 3 .....(2) 

In the equation x + y = 5

Putting x = 0 

x + y = 5 

0 + y = 5

y = 5

Putting y = 0

x + y = 5

x + 0 = 5

x = 5

Putting y = 3

x + y = 5

x + 3 = 5

x = 5 - 3

x = 2

 

x	0	5	2
y	5	0	3

In the equation x – y = 3

Putting x = 3

x – y = 3

3 – y = 3

y = 0

Putting x = 0

x – y = 3

0 – y = 3

y = –3

Putting x = 5

 x – y = 3

5 – y = 3

5 – 3 = y

y = 2

x	3	0	5
y	0	−3	2

The point of intersection of the two lines is (4, 1).