`(7a^(2) - 63b^(2)) =`?

The equation of the hyperbola with centre at the origin the length of transverse axis 6 and one focus is (0,4) is (i) 9x^(2) - 7y^(2) = 63 (ii) 7y^(2) - 9x^(2) = 63 (iii) 9y^(2) - 7x ^(2) = 63 (iv) 7x^(2)-9y^(2)=63

Factorise : 5a^(2) - b^(2) - 4ab + 7a - 7b

The distance between the foci of the conic 7x^(2) - 9y^(2) = 63 is equal to

((63+36)^(2)+(63-36)^(2))/(63^(2)+36^(2)) =?

If (7a^2 +2b^2)/(7a^2 -2b^2) = (113)/(13) , find the value of a/b .

Subtract : 5a ^(2) b ^(2) c ^(2) from -7a ^(2) b ^(2) c ^(2)

(63)^(2)-(12)^(2)=?