`(-4)/(13)+0=0+(-4)/(13)`

Name the property of multiplication of rational number illustrated by the statement: (2)/(13)x0=0=0x(2)/(13)

Show that the three lines with direction cosines quad (12)/(13),(-3)/(13),(-4)/(13),(4)/(13),(12)/(13),(3)/(13);(3)/(13),(-4)/(13),(12)/(13) are mutually perpendicular.

Check if lines with direction-cosines : lt (12)/(13) , - (3)/(13) , - (4)/(13) gt , lt (4)/(13) , (12)/(13), (3)/(13) gt , lt (3)/(13) , (4)/(13) , (12)/(13) gt are mutually perpendicular .

Show that the three lines with direction cosines (12)/(13),(-3)/(13),(-4)/(13);4/(13);(12)/(13),3/(13);3/(13),(-4)/(13),(12)/(13) are mutually perpendicular.

sqrt((0.361)/(0.00169))=?(1.9)/(13) (b) (19)/(13)(c)(1.9)/(130) (d) (190)/(13)

Let P(A)=7/(13), P(B)=9/(13) and P(AnnB)=4/(13) . Then P( A //B)= 5//9 b. 4//9 c. 4//13 d. 6//13

Prove that: 2cos (pi)/(13) cos (9 pi)/(13)(3 pi)/(13)(5 pi)/(13)=0

Two circles, each having radius 4, have a common tangent given by 3x+2y-6=0 at (2, 0) . Then their centres are : (A) (2+ 5/sqrt(13), 8/sqrt(13)), (2- 5/sqrt(13) , (-8)/sqrt(13)) (B) (2+ 12/sqrt(13), 8/sqrt(13)) , (2- 12/sqrt(13), (-8)/sqrt(13)) (C) (2, 3), (4, 5) (D) none of these

Find the sum of the series (5)/(13)+(55)/(13)^2+(555)/(13)^2+(5555)/((13)^4) …………..up to prop .