Vx + 2(V-1)y = 1
(V-5)x+(V-5)y = 2
In the above system of linear equations, (x,y) is the solution and V /= 5 (not equal) is a constant. For what value of V, the above two lines dont intersect?
a) 4
b) 1
c) 0
d) 2
Answer is D but how do you get it?
First rearrange both equations in slope-intercept form:
1st eqn: y = -Vx/(2*(V-1)) + 1/(2*(V-1)) slope = -V/(2*(V-1))
2nd eqn: y = -x + 2/(V - 5) slope = -1
The two lines will never intersect if they are parallel. They are parallel if their slopes are the same, so set the two slopes equal to each other and solve for V.