Algebra 1 (Polynomials Question)

Question

I don't understand this at all please help!

So the four equations are :

A: (2x+1)(x+5)

B: (x^2+1)(x+5)

C: (t+1)(t+5)

D: x(x+5)

And we have to answer: I think that expression ------ doesn't belong because and Expression ----- also doesn't belong because -----

Thank you so much!

Answer 1

b) does not belong because when you multiply this one out it is third degree or cubic polynomial while the other three expressions are second degree or quadratic when they are multiplied out

Answer 2

When we simplify all the options, we get

A: (2x+1)(x+5) => 2x² + 11x + 5

B: (x^2+1)(x+5) => x³ + 5x² + x + 5

C: (t+1)(t+5) => t² + 6t + 5

D: x(x+5) => x² + 5x

When you observe the above simplified expressions, you find one common thing.That is all have same degree (2), except option B, which has a degree 3 which is cubic. Hence B is the expression doesn't belong here.And the reason: since, it's cubic (degree 3) whereas all other expressions are quadratic (degree 2).

Hope this helps!

Answer 3

This question doesn't make too much sense to me. I would start by multiplying all these out using either FOIL or the distributive property.

A:.2x²+11x+5

B: x³+5x²+x+5

C: t²+6t+5

D: x²+5x

You could say that B doesn't belong because the degree (highest exponent) is 3 while the others are all 2. You could also say that B and D don't belong because A and C are both trinomials (3 terms) while B is a polynomial (anything with 4 or more terms) and D is a binomial (2 terms)