Question

x = 2 and y = - 1 is the solution of the equation Lax - y = 3 (b) 2x + y = - 3 (C) x - 2y = 0 (d) x+ y = 3​

Answer 1

Answer:

The given system of equations is

5x+2y−k=0

10x+4y−3=0

This system of equation is of the form

a

1

x+b

1

y+c

1

=0

a

2

x+b

2

y+c

2

=0

where a

1

=5,b

1

=2,c

1

=−k

and a

2

=10,b

2

=4 and c

2

=−3

For infinitely many solutions, we must have

a

2

a

1

=

b

2

b

1

=

c

2

c

1

i.e.,

10

5

=

4

2

=

−3

−k

⇒

2

1

=

3

k

⇒k=

2

3

Hence, the given system of equations will have infinitely many solutions, if k=

2

3

.

Answer 2

Answer:

option a

Step-by-step explanation:

x-y=3

2 - (-1) = 3

2 + 1 = 3

3 = 3

L.H.S = R.H.S