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

Answer:

Option A. 4+5i

Step-by-step 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

$4+\sqrt{-25}$

Remember

$i=\sqrt{-1}$

substitute

$4+\sqrt{-25}=4+\sqrt{(-1)(25)}=4+5\sqrt{(-1)}=4+5i$