分解 6a(a+6)2/3 + 8(a+6)1/3
代数表达式由变量和常数以及诸如加法、减法等代数运算组成。这些表达式由项组成。代数表达式是对任何变量进行加减乘除等运算时的方程。
A combination of terms by the operations such as addition, subtraction, multiplication, division, etc is termed as An algebraic expression (or) a variable expression.
Examples: 2x + 4y – 7, 3x – 10, etc.
上述表达式是在未知变量、常数和系数的帮助下表示的。这三个术语的组合称为表达式。与代数方程不同,它没有边或“等于”符号。
代数表达式的类型
代数表达式根据表达式中存在的项数分为三种类型:
- 单项式
- 二项式
- 多项式表达式
单项式
只有一项的表达式称为单项式表达式。
Examples of monomial expressions include 5x4, 3xy, 2x, 5y, etc.
二项式
具有两项且不同的代数表达式称为二项式表达式
Examples of binomial include 2xy + 8, xyz + x2, etc.
多项式表达式
具有多个非负整数指数的变量的表达式称为多项式表达式。
Examples of polynomial expression include ax + by + ca, x3 + 5x + 3, etc.
其他类型的表达
除了单项式、二项式和多项式类型的表达式之外,我们还有其他表达式
- 数值表达式
- 变量表达式
数值表达式
仅由数字和运算组成但从不包含任何变量的表达式称为数字表达式。
Some of the examples of numeric expressions are 14 + 5, 18 ÷ 2, etc.
变量表达式
包含变量以及用于定义表达式的数字和操作的表达式称为变量表达式。
Some examples of a variable expression include 4x + y, 5ab + 53, etc.
一些重要的代数公式
有一些基本使用的代数表达式术语,
(a + b)2 = a2 + 2ab + b2
(a – b)2 = a2 – 2ab + b2
(a + b)(a – b) = a2 – b2
(x + a)(x + b) = x2 + x(a + b) + ab
(a + b)3 = a3 + b3 + 3ab(a + b)
(a – b)3 = a3 – b3 – 3ab(a – b)
a3 – b3 = (a – b)(a2 + ab + b2)
a3 + b3 = (a + b)(a2 – ab + b2)
示例:如果 2x 2 +3xy+4x+7 是代数表达式。确定方程。
解决方案:
2x2, 3xy, 4x, and 7 are the Terms
Coefficient of term: 2 is the coefficient of x2
Constant term: 7
Variables: here x, y are variables
Factors of a term: If 2xy is a term, then its factors are 2, x, and y.
Like and Unlike terms : Example of like and unlike terms:
- Like terms: 4x and 3x
- Unlike terms: 2x and 4y
因式分解 6a(a+6) 2/3 + 8(a+6) 1/3
解决方案:
Given [6a(a+6)2/3] + [8(a+6)1/3]
From above expression we will factorize
= [2.3a(a+6)2/3] + [(2)3 (a+6)1/3]
= 2(a+6)1/3 [{3a(a+6)1/3 + 22]
= 2(a+6)1/3 {3a(a+6)1/3 + 4}
= 2(a+6)1/3 {3a(a+6)1/3 + 4}
类似问题
问题 1:分解和简化 x 4 + 4?
解决方案:
Given x4 + 4
Add or subtract 4x2 from the above given term
Therefore
= x4 + 4 + 4x2 – 4x2
= x4 + 4x2 + 4 – 4x2
= (x2 + 2)2 – 4x2
= (x2 + 2)2 – (2x)2
Now we will use
(a + b)(a – b) = a2 – b2
= (x2 + 2x + 2) (x2 – 2x + 2)
问题 2:化简 x(x + z) – y (y + z)
解决方案:
Given: x(x+z) – y ( y + z)
= x2 + xz – y2 – yz
= (x2 – y2) + (xz – yz)
= (x-y)(x + y) + z (x- y)
So by taking common (x-y)
= (x-y) {x + y+ z}
问题 3:求解 x = 4:x 2 – 4x + 5
解决方案:
x2 – 4x + 5
= 42 – (4 × 4) + 5
= 16 – 16 + 5
= 0 + 5
= 5
问题 4:求解 (5 – 10w)(-w 2 )
解决方案:
(5 – 10w)(-w2)
By simplifying
= (5 – 10w)(-w2)
= [5 × (-w2)] – [10w × -(w2)]
= -5w2 – (-10w3)
= -5w2 + 10w3
= 5w2 (-1 + 2w)
= 5w2 (2w – 1)
问题 5:简化:5 – 2(x – 2)。
解决方案:
Given expression, 5 – 2(x – 2)
= 5 – 2x + 4
= 9 – 2x
= -2x + 9