So, all values that are 0 or greater will make the inequality true:
0, 5, 10
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* Parentheses are eliminated using the distributive property. The factor outside parentheses multiplies each of the terms inside. Pay attention to signs.
The imaginary unit belongs to the set of complex numbers, denoted by . These numbers take the form , where are any real numbers.
The set of real numbers, , is a subset of , where each number in can be obtained by taking and letting be any real number.
But any number in with non-zero imaginary part is not a real number. This includes .
"is it possible that i can use an imaginary number for a real number"
I'm not sure what you mean by this part of your question. It is possible to represent any real number as a complex number, but not a purely imaginary one. All real numbers are complex, but not all complex numbers are real. For example, 2 is real and complex because .
There are some operations that you can carry out on purely imaginary numbers to get a purely real number. A famous example is raising to the -th power. Since , we have