Question

Solve the following simultaneous equations graphically.

2x – 3y = 4 ; 3y – x = 4

Answer 1

i. 2x – 3y = 4

y = `(2"x" - 4)/3`

Put x = 2 

y = `(2(2) - 4)/3`

= `(4 - 4)/3`

= `0/3`

= 0

Put x = 3.5

y = `(2(3.5) - 4)/3`

= `(7 - 4)/3`

= `3/3`

= 1

Put x = 1

y = `(2(1) - 4)/3`

= `(2 - 4)/3`

= `-2/3`

= −0.6

x	2	3.5	1
y	0	1	−0.6

ii. 3y – x = 4

y = `(4 + "x")/3`

Put x = –4

y = `(4 + (-4))/3`

= `0/3`

= 0

Put x = 2

y = `(4 + 2)/3`

= `6/3`

= 2

Put x = −1

y = `(4 + (−1))/3`

= `(4 - 1)/3`

= `3/3`

= 1

x	−4	2	−1
y	0	2	1

 

​The point of intersection of the two lines is (8, 4).