Solution:-
Firstly we must know what complex Number is .
Complex number - The number in the form of a + bi ,where a is real part and bi is Imaginary part is called a complex number . Also here value of i ( read as iota ) is √-1 . It can't be represented on the number line and is represented on the Argand Plane .
So , here the complex number given to us is 7 + 9i .
So , it can be written as ,
= 7 + 9i .
= 7 + 9√-1 .
= 7 + √9 × √9 × √-1 .
= 7 + √ 81 × -1 .
= 7 + √-81 .
[tex]\boxed{\green{\bf\purple{\dag }Hence\: correct\: option\:is\:[d].}}[/tex]
