65 + 9393445345643 + 3 是多少？

通过诸如加法、减法等数学运算连接的不同项的组合称为代数表达式。当说代数表达式中涉及项时，这意味着这些项可以是变量、常数或变量和常数的组合，其中两者通过乘法运算符连接以计为一个条件。

代数表达式的类型

根据表达式中存在的项数，主要有四种类型的代数表达式。这四种类型是单项式、二项式、三项式和多项式。让我们了解它们的定义，

1. 单项式：仅包含一个非零项的表达式称为单项式。例如，2 是一个单项式表达式，其中只有一个常数，4ab ⁴也是一个单项式表达式，其中有 1 个常数和 2 个变量。
2. 二项式表达式：包含两个非零项的表达式称为二项式表达式。例如，p+q 是一个包含 2 个变量的二项式表达式。
3. 三项式表达式：包含三个非零项的表达式称为三项式表达式。例如，-8p+q ⁵ + 8r 是一个三项式表达式，其中包含 3 个变量。
4. 多项式表达式：包含两个或两个以上非零项的表达式称为多项式表达式。例如，-12p+q ⁵是一个多项式表达式，其中包含 3 个变量。

65 + 9393445345643 + 3 是多少？

解决方案：

Looking at them in terms of algebraic expressions, it can be observed that they are a monomial expression after simplifying, adding 3 constant terms will provide a constant term. 

= 65 + 9393445345643 + 3

= 9,393,445,345,711

Therefore, the final answer is a monomial expression containing a constant.

现在这个概念已经很清楚了。让我们继续了解一些相似之处，然后了解代数表达式中的一些更复杂的计算，

类似问题

问题 1：31 + 7845 + 2 是多少？

解决方案：

Looking at them in terms of algebraic expressions, it can be observed that they are a monomial expression after simplifying, adding 3 constant terms will provide a constant term.

= 31 + 7845 + 2

= 7,878

Therefore, the final answer is a monomial expression containing a constant.

问题 2：23 + 5 + 1009700 是多少？

解决方案：

Looking at them in terms of algebraic expressions, it can be observed that they are a monomial expression after simplifying, adding 3 constant terms will provide a constant term.

= 23 + 5 + 1009700

= 1,009,728

Therefore, the final answer is a monomial expression containing a constant.

问题3：添加给定的代数表达式，

1. 2x ² + 4y + 89
2. 51x ² + 3xy + 78

解决方案：

The most important thing to notice while adding two algebraic expressions is the similarities in terms, simply add the terms that are similar to each other. Here, x² is common, they can be added, the contents can be added, while y and xy are different terms, so they will be written directly.

= (2x² + 51x²) + 4y + 3xy + (89 + 78)

= 53x² + 3xy + 4y + 167

Therefore, the above expression is the polynomial obtained after addition.

问题 4：添加给定的代数表达式，

1. 5p ² + 200q + 80
2. 43p ² + 4pq + 10

解决方案：

The most important thing to notice while adding two algebraic expressions is the similarities in terms, simply add the terms that are similar to each other. Here, x2 is common, they can be added, the contents can be added, while y and xy are different terms, so they will be written directly.

= (5p² + 43p²) + 200q + 4pq + (80 + 10)

= 48p2 + 4pq + 200q + 90

Therefore, the above expression is the polynomial obtained after addition.

问题5：识别多项式的类型，

1. 3
2. 4x ²
3. 5pq + 5r ³ + 9

回答：

1. 3 is a monomial expression.
2. 4x² is a monomial expression with a constant and a variable.
3. 5pq + 5r³ + 9 is a trinomial expression.

问题6：识别多项式的类型，

1. 90
2. 14许²
3. 35yz + 9x ³ + 1

回答：

1. 90 is a monomial expression.
2. 14xu² is a monomial expression with a constant and a variable.
3. 35yz + 9x³ + 1 is a trinomial expression.