1.

{{:(5x-3y=10),(6y=kx-42):} In the system of linear equations above, k represents a constant. If the system of equations has no solution, what is the value of 2k?

Answer»

`5/2`
5
10
20

Solution :Start by recognizing that for two lines to be parallel, the coefficients for x must be identical in the two equations, dutto for the coefficients for y. Manipulate the second EQUATION so that it is in the same format as the first one:
`kx - 6y=42`
The y-coefficient in the first equation, `5x-3y=10, is 3.` Divide the second equation by 2 in ORDER to make the y-coefficients in both equatinos equal:
`k/2x -3y=21`
Now set the x-coefficient equal to the x-coefficient in the first equation:
` k /2=5`
`k=10`
Note that the question asks for the value of 2K, so the correct answer is (D), 20.


Discussion

No Comment Found

Related InterviewSolutions