The ratio of the measures of two supplementary angles is 7: 3. find the measures of the angles.
a. 126° and 54°
b. 72° and 18°
c. 159° and 21°
d. 69° and 21°

Supplementary angles are angles in which the total is equal to 180 degrees when summed. when the ratio of the angles is 7:3 we let x be angle 1 hence, 

7x + 3x = 180
simplifying, 
10 x =180
x = 18

Hence angle 1 is 126 degrees and angle 2 is 54 degrees. Answer is A. 

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 *_*