Method III in the method to test the equality of two rational numbers `a/b and c/d ` we use the following result : ` a/b = c/d <=> a xx d = b xx c `

Let A = Q xx Q, where Q is the set of all rational numbers, and * be abinary operation defined on A by (a, b) * (c, d) = (ac, b + ad), for all (a, b) (c, d) in A.Find the identity element in A.

Two planes are perpendicular to one another. One of them contains vectors a and b and the other contains vectors c and d, then (a xx b).(c xx d) equals

Let ~ be a relation defined on N xx N as follows: (a,b),(c,d) in N xx N, (a,b) ~ (c,d) if ad = bc, then

Show : ( a/b times c/d ) = ( a times c )/ ( b times d )

If a+sqrt(b)=c+sqrt(d) where a and c are rational numbers sqrt(b) and sqrt(d) are irrational numbers then prove that a=c and b=d .

The LCM and HCF of two rational numbers are equal,then the numbers must be (a) prime (b) co-prime (c) composite (d) equal

Let a,b,c d be real numbers such that for every natural number n. Then |a|+|b|+|c|+|d| is equal to

For rational numbers (a)/(b), (c )/(d) and (e )/(f) we have (a)/(b) xx ((c )/(d) +(e )/(f))= ______ + _______.