Question

How many terms are there in each expression?$$5-2 x^{3}-7 x+x^{2}$$

Short answer

There are 4 terms in the expression.

Step-by-step solution

Identify the terms in the expression

Review the given expression and identify each separate term. A term in an algebraic expression is a constant or a variable raised to an exponent, which can be combined using addition or subtraction. Look for parts of the expression that are separated by a plus (+) or minus (-) sign.

Count the number of terms

Count each distinct term identified in Step 1. Here, the separate terms are '5', '-2x^3', '-7x', and 'x^2'.

Key concepts

Terms in Algebra

In the world of algebra, understanding the basic building block—terms—is crucial. A term is defined as a single mathematical expression which may include numbers, variables (like x or y), and possibly exponents (indicating the power to which a variable is raised). An algebraic expression can have one or more terms, which are separated by plus ((+)) or minus ((-)) signs. For example, in the expression (5-2 x^{3}-7 x+x^{2}), each number or variable along with its coefficient and exponent combination is a separate term.

Counting Terms

Counting terms correctly is an essential skill in algebra. To identify the number of terms in an expression, look for the individual components that are not connected by multiplication or division. Each term is standalone and usually connected to another term by addition or subtraction. Take the expression (5-2 x^{3}-7 x+x^{2}); if we break it down, we find there are four terms: '5', '(-2x^3)', '(-7x)', and '(x^2)'. Remember, terms that involve the same variable raised to the same power (like '(3x^2)' and '(4x^2)') can be combined to form a single term, while different powers or variables mean separate terms.

Algebraic Terms Identification

Identifying terms in algebraic expressions is a step-by-step process. Start by scanning for plus and minus signs, as they are the separators. Next, examine each piece isolated by those separators—these are your terms. They may consist of a coefficient (a numerical multiplier of a variable), the variable itself (often a letter like x), and an exponent.
In our example, the coefficients are '5' (which is actually a constant term because it doesn't multiply a variable), '-2', '-7', and the implied '1' in '(x^2)'. The variable is 'x', and it comes with different exponents or none at all. Being able to distinguish between these allows for correct manipulation and simplification of algebraic expressions.

Polynomial Expressions

Polynomial expressions are a type of algebraic expression containing several terms. They can be classified as monomials (one term), binomials (two terms), trinomials (three terms), or polynomials (more than three terms). The general form of a polynomial expression is an aggregation of terms where variables are raised to whole number exponents and may have coefficients.
With the given example, (5-2 x^{3}-7 x+x^{2}), we're looking at a polynomial with four terms, which makes it neither a monomial, binomial, nor trinomial. It's essential to understand polynomials since they form the basis of many algebraic operations, from factoring to finding zeroes.