How do I solve 28-0.3y=0.7y-12

28-0.3y=0.7y-12 add 0.3y
+0.3y +0.3y
28=0.7y-12+0.3y
28=y-12 add 12
+12 +12
28+12=y
40=y
y=40 solved for y

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 *_*