If `a, b, c` are variables such that `21a + 40b + 56c=0` then the family of lines `ax+by+c=0` passes through (A) `(7/14, 9/4)` (B) `(4/7, 3/8)` (C) `(3/8, 5/7)` (D) `(2, 3)`

If a ,b ,c are variables such that 3a+2b+4c=0 , then show that the family of lines givenby a x+b y+c=0 pass through a fixed point. Also, find that point.

If 6a^2-3b^2-c^2+7ab-ac+4bc=0 then the family of lines ax+by+c=0,|a|+|b| != 0 can be concurrent at concurrent (A) (-2,3) (B) (3,-1) (C) (2,3) (D) (-3,1)

The straight lines 4a x+3b y+c=0 passes through? , where a+b+c =0 (a) (4,3) (b) (1/4,1/3) (1/2,1/3) (d) none of these

If 6a^2-3b^2-c^2+7ab-ac+4bc=0 then the family of lines ax+by+c=0,|a|+|b| != 0 can be concurrent at concurrent

If 3a + 2b + 6c = 0 the family of straight lines ax+by = c = 0 passes through a fixed point . Find the coordinates of fixed point .

Find the equation of the plane passing through A(2,2,-1),B(3,4, 2) and C(7,0,6) .

If a, b, c are real numbers satisfying the condition a+b+c=0 then the rots of the quadratic equation 3ax^2+5bx+7c=0 are

The lines ax + by + c = 0, where 3a + 2b + 4c= 0, are concurrent at the point (a) (1/2 ,3/4) (b) (1,3) (c) (3,1) (d) (3/4 ,1/2)

In a family of 3 children, the probability of having at least one boy is 7/8 (b) 1/8 (c) 5/8 (d) 3/4

(i) If a, b, c, are in A.P. then show that ax….+….by +c=0 passes through a fixed point. Find then fixed point. (ii) If 9a^(2)+16b^(2)-24ab-25c^(2)=0, then the family of straight lines ax+by+0 is concurrent at the point whose co-ordinates are given by "________" (iii) If 3a+4b-5c=0, then the family of straight lines ax+by+c=0 passes through a fixed point. Find the coordinates of the point.