Question

If the two equations 2x+y=1 , 4x+2y=k have infinite number of solutions then what is the value of K ?

Answer 1

Answer: k=2

Explanation:

If the two equations 2x+y=1, 4x+2y=k have infinite number of solutions, it means that the two equations are dependent and represent the same line. To check this, we can find the ratio of the coefficients of x and y in the two equations:2/4 = 1/2

1/2 = k/1

From the first ratio, we can see that the coefficient of x in the second equation is twice that of the first equation.

Similarly, the coefficient of y in the second equation is twice that of the first equation. Therefore, the second equation is just a multiple of the first equation.Solving the first equation for y, we get y = 1-2x. Substituting this into the second equation, we get:4x + 2(1-2x) = k

4x + 2 - 4x = k

2 = k

Therefore, the value of k is 2.

Answer 2

k=2

Explanation:

2x+y=1 (1)

(1)×2: 4x+2y= 2

The y-intercept of both lines must be the same as if the y-intercept is different, it will have no solutions instead of infinite solutions. In order to achieve infinite solutions, both lines must be on the same points and have same gradient and same y-intercept.

Hence, k= 2