Question

For what value of k the following system of equation
no solution（1）2x +ky=1 and 3x-5y-=7（2）Kx-5y-2 and 6x+2y=7
（3） 2x +Ky=1 and 5x-7y=5​

Answer 1

Answer:

Step-by-step explanation:

Taking 1st option,

2x + ky=1

3x - 5y=7

Now multiplying 1st equation with 3 and 2nd with 2.

2x + ky=1 * 3

3x - 5y=7 *2

6x + 3ky=3

6x - 10y=14

Now substarcting both the equations.

6x + 3ky=3

-6x + 10y=-14

3ky + 10y = -11 ---- (1)

Doing similar calculation for 3rd option, we will get

5ky + 14y = -5 ----(2)

Now multiplying (1) with 5 and (2) with 3

15ky + 50y = -55

15ky + 42y = -15

Substarcting the above equation, we get

8y = -40

y = -5

Now substitute y=-5 in (1)

3k(-5) + 10*-5 = -11

-15k - 50 = -11

-15k = 50-11

-15k = 39

k = 39/15 = 13/5