Step-by-step explanation:
Given
[tex]\left(x+7\right)^7[/tex]
solving the expression
[tex]\left(x+7\right)^7=0[/tex]
[tex]\mathrm{Using\:the\:Zero\:Factor\:Principle:\quad \:If}\:ab=0\:\mathrm{then}\:a=0\:\mathrm{or}\:b=0\:\left(\mathrm{or\:both}\:a=0\:\mathrm{and}\:b=0\right)[/tex]
[tex]\mathrm{Solve\:}\:x+7=0[/tex]
[tex]\mathrm{Subtract\:}7\mathrm{\:from\:both\:sides}[/tex]
[tex]x+7-7=0-7[/tex]
Simplify
[tex]x=-7[/tex]
[tex]\mathrm{The\:solution\:is}[/tex]
[tex]x=-7[/tex]
A complex number follows this form
[tex]a + ib[/tex]
Here:
If b = 0, then the number is a real number.
As -7 has contains only the real part, so the root -7 is the real root.