(a) Determine the value of a if the straight line `ax+7y=3(a-2)` passes through the origin.

(b) Determine the value of a if the straight line 2x+ay=10(a-30) passes through the point (1,2)) .

(ix) Find the value of a if the straight line 10x+(a-1)y=11(a-3) passes through the origin.

(xv) Which one of the following straight line passes through the origin ?

Show that the circle x^(2) + y^(2) + 4(x+y) + 4 = 0 touches the coordinates axes. Also find the equation of the circle which passes through the common points of intersection of the above circle and the straight line x+y+2 = 0 and which also passes through the origin.

Show that the circle x^(2) + y^(2) + 6(x-y) + 9 = 0 touches the coordinates axes. Also find the equation of the circle which passes through the common points of intersection of the above circle and the straight line x-y+4 = 0 and which also passes through the origin.

The condition for which the straight line ax +by +c=0 will pass throught the origin is -

Find the equation of the straight line which passes through the origin and makes angle 60^0 with the line x+sqrt(3)y+sqrt(3)=0 .

Plot of rate of reaction against the concentration of the reactant gives a straight line passing through the origin. The order of the reaction is ...........

Show that the straight line joining the points (-3,2) and (6,-4) passes through the origin .

Show that the straight line joining the points (4,-3) and (-8,6) passes through the origin .