What is a type expression that contains a variable or variables

6+a=12 or 13+b=23 a variable is when there is a letter with something you add ,subtract ,multiply, and divide something.

Answer to your question: a. the fundamental theorem of algebra tells you that the equation will have two complex roots since the degree of the polynomial is 2. the roots are ​ x=1±i7√2 .number of roots=degree of polynomialhere, degree of polynomial is 2 so number of roots will be 2.hope it *_*