Question

Which expression represents the number 4+−25−−−−√ rewritten in a+bi form?

A. 4+5i
B. 4i+5
C. 4−5i
D. 0+9i
E. 5+4i

Answer 1

Option A. 4+5i

Explanation:

we know that

The form of (a + bi) is known as a complex number where a and b are real numbers and i is an imaginary number equivalent to the square root of negative 1

we have the number

`4+√(-25)`

Remember

`i=√(-1)`

substitute

`4+√(-25)=4+√((-1)(25))=4+5√((-1))=4+5i`