[(31000)/(30030)quad " is "[a=(x)/(x+y)" and "b=(y)/(x-y)" then "(ab)/(a+b)],[+(1)/(64x^(3))," is: "],[[" (A) "(xy)/(x^(2)+y^(2))," (B) "(x^(2)+y^(2))/(xy)]]

If a=(x)/(x+y) and b=(y)/(x-y), then (ab)/(a+b) is equal to (a) (xy)/(x^(2)+y^(2)) (b) (x^(2)+y^(2))/(xy)( c) (x)/(x+y) (d) ((y)/(x+y))^(2)

If (sin (A+B))/( sin (A-B )) = (x+y)/(x-y) , then x/y

(a)/(x)-(b)/(y)=0,(ab^(2))/(x)+(a^(2)b)/(y)=a^(2)+b^(2)

If A={(x,y):y=e^(-x)}" and "B={(x,y):y=-x} . Then,

If (x+1)/(x-1)=(a)/(b) and (1-y)/(1+y)=(b)/(a), then the value of (x-y)/(1+xy) is (2ab)/(a^(2)-b^(2)) (b) (a^(2)-b^(2))/(2ab) (c) (a^(2)+b^(2))/(2ab) (d) (a^(2)-b^(2)backslash)/(ab)

If A =x+y and B=x-y find A+B

Solve for x and y. (a-b)x+(a+b)y=a^(2)-2ab-b^(2) , (a+b)(x+y)=a^(2)+b^(2)