Tickets to a school basketball game cost $4 for students and $7 for adults. at the end of the night, 168 tickets are sold for a total of $861. how many tickets are sold

4s+7a=861
s+a=168

This can be solved using either elimination or substitution. I am going to use substitution.

Solve s+a=168 for s
s=168-a

Replace 168-a for s in 4s+7a=861
4(168-a)+7a=861
672-4a+7a=861

Solve for a
672+3a=861
3a=189
a=63

Substitute 63 for a in s=168-a
s=168-63=105

So, s=105 student tickets and a=63 adult tickets

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 *_*