Question

Which expression simplifies the following expression properly: LaTeX: 5i^4+2i^3+\sqrt{-81} 5 i 4 + 2 i 3 + √ − 81 ?

Answer 1

We know that, (A+B)(C+D)=A×(C+D)+B×(C+D)

=AC+AD+BC+CD

(i) (3+

3

)(2+

2

)=(6+2

3

+3

2

+

6

)

(ii) (

5

+

2

)

2

=(5+2+2

10

)=(7+2

10

)

(iii) (3+

3

)(3−

3

)=(9−3)=6

(iv) (

5

−

2

)(

5

+

2

)=(5−2)=3