How do you decide if a decimal is a rational number?

You decide if it has a pattern if it is a repeating pattern then it is a rational number decimal however if it a decimal with no pattern it is irrational

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 *_*