Find the solution of this system of equations -5x=-21+6y -5x+y=-84

-5x - 6y = -21
5x - y =. 84

-7y = 63

y= -9

-5x = -21 - 54

-5x = -75

x = 15

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 *_*