To determine which of the given expressions is a binomial, we need to understand what a binomial is. A binomial is an algebraic expression that contains exactly two terms. Each term can be a number, a variable, or a product of numbers and variables.
Let's examine each of the given choices:
Choice A: [tex]\(7x + 21\)[/tex]
- This expression has two terms: [tex]\(7x\)[/tex] and [tex]\(21\)[/tex].
Choice B: [tex]\(\frac{3}{2}\)[/tex]
- This is just a single number, which is one term.
Choice C: [tex]\(8x^2 + 6x + 5\)[/tex]
- This expression has three terms: [tex]\(8x^2\)[/tex], [tex]\(6x\)[/tex], and [tex]\(5\)[/tex].
Choice D: [tex]\(19x^4\)[/tex]
- This is a single term, involving the variable [tex]\(x\)[/tex] raised to the fourth power, and multiplied by 19.
Now we see, among the given choices, only Choice A has exactly two terms.
Thus, the binomial is:
[tex]\[ A. 7x + 21 \][/tex]
