If `a/3=b/4=c/7` , the value of `(a+b+c)-:c` is (a) `1/7` (b) `1/2` (c) `2` (d) `7`

If alpha\ a n d\ beta are the roots of 4x^2+3x+7=0 then the value of 1/alpha+1/beta is a) 4/7 b) -3/7 c) 3/7 d) -3/4

If a^(3) =1+7, 3^(3) = 1+7+b, 4^(3) = 1+7 +c , then the value of a+ b+ c is

If (a)/(b)=(4)/(5) and (b)/(c)=(15)/(16), then (c^(2)-a^(2))/(c^(2)+a^(2)) is (a) (1)/(7)( b) (7)/(25)( c) (3)/(4) (d) None of these

If a : b=3:4, b : c4:7, t h e n(a+b+c)/c is equal to 1 b. 2 c. 3 d. 7

If in A B C ,A=pi/7,B=(2pi)/7,C=(4pi)/7 then a^2+b^2+c^2 must be (a) R^2 (b) 3R^2 (c) 4R^2 (d) 7R^2