which of the following expressions is equal to 2x^2+18 ?

The expression [tex]2x^{2} +18[/tex] is equal to [tex](2x-6i)(x+3i)[/tex].
The correct answer is option C.
[tex]i^{2}=-1[/tex]
A. [tex](2x-9i)(x-2i)[/tex]
[tex]= 2x(x)-2x(2i)-9i(x)-9i(-2i)\\=2x^{2} -4xi-9xi-18\\=2x^{2} -13xi-18[/tex]
[tex]2x^{2} -13xi-18[/tex] ≠ [tex]2x^{2} +18[/tex]
B. [tex](2x-6i)(x-3i)[/tex]
[tex]=2x^{2}-6xi-6xi-18\\=2x^{2} -12xi-18[/tex]
[tex]2x^{2} -12xi-18[/tex] ≠ [tex]2x^{2} +18[/tex]
C. [tex](2x-6i)(x+3i)[/tex]
[tex]=2x^{2} +6xi-6xi+18\\=2x^{2} +18[/tex]
[tex]2x^{2} +18=2x^{2} +18[/tex] [tex](LHS=RHS)[/tex]
Therefore, the expression [tex]2x^{2} +18[/tex] is equal to [tex](2x-6i)(x+3i)[/tex].
For more information:
ttps://brainly.com/question/23672426