Question

Graphically, the pair of equations 7x-y = 5; 21x -3y = 10 represents two lines which are
a) intersecting at one point
b) parallel
c) intersecting at two points
d) coincident

Answer 1

ANSWER

The equations are x=a and y=b.

The graph of x=a is a line parallel to y-axis and y=b is a line parallel to x-axis.

∴ the angle between them is 90

o

, i.e. they intersect.

So, the equations are consistent.

Now solving simultaneously, the solution is (a,b).

So, the point of intersection is (a,b).

Hence, option D is correct.