Question

Solve graphically the following system of linear equations. Also find the coordinates of the points where the lines meet axis of y. [4] 2x + y – 11 = 0, x – y – 1 = 0

Answer 1

Q1. x + y = 3; 2x + 5y = 12

Sol:

2x + 5y = 12

We have,

x + y = 3

When y = 0 we have x =3

When x= 0 we have y =3

Thus we have the following table giving points on the line x+y =3

X 0 3

Y 3 0

Now, 2+5y= 12

= y = 12−2x5

When x= 1, we have

= y = 12−2(1)5 = 4

Thus we have the following table giving points on the line 2x+5y=12

X 1 -4

Y 2 4

Graph of the equation x+y =3 and 2x+5y=12 is

1

Clearly two lines intersect at a point P (1,2)

Hence x= 1 and y = 2