两个数字的和是 20，它们的差是 4。找出数字

算术是数学的一个分支，它处理数字的性质和操作，包括数学的基本运算，如加法、减法等。这些类型的问题基本上给出了一些条件，并且需要从中获得方程，使得未知数variables 等于方程的数量，这将确保可以通过对这些方程使用一些基本的算术运算来找到变量的值。

查看下面的问题陈述以获得更好的理解

哪两个数的和为20，差为4？

给出的问题是给出了 2 个未知数，其和等于 20，差为 4。第一个要求是根据提供的信息创建两个方程，两个方程将包含两个未知数，并且它们可以很容易地求解通过替代方法或消除方法，让我们逐步解决问题陈述，

分步说明

Since the 2 numbers are unknown, assume them to be two natural numbers  x and y

Given: Sum of x and y=20

Therefore, it can be written as,

x+y = 20  ⇢  (1)

Given, Difference of x and y = 4

which can be written as

x−y = 4  ⇢  (2)

Now it can be observed that 2 equations are formed and there are 2 unknown variables, which implies that on performing arithmetic operations on these 2 equations, the value of the unknown variables can be easily found.

Hence, on Adding equation (1) & equation (2) we get,

2x = 24

which implies x = 12

Since, the value of x is there, put x =12 in equation (1) and get y = 8

Therefore, we have obtained the 2 numbers ⇢  The first number is 12 and the second number is 8.

类似问题

问题 1：给定两个差为 6 且和为 10 的数，找出这两个数。

解决方案：

Step-by-step explanation:

Since the 2 numbers are unknown, assume them to be two natural numbers  x and y

Given: Difference of x and y = 6

Therefore,

x-y = 6  ⇢  (1)

Given: Sum of x and y = 10

which can be written as

x+y = 10  ⇢  (2)

Now it can be observed that 2 equations are formed and 2 unknown variables are obtained, which implies that on performing arithmetic operations on these 2 equations the value of the unknown variables can be obtained.

Hence, on Adding equation (1) & equation (2),

2x = 16

which implies x = 8

Since value of x is known, put x = 8 in equation (1) and get y = 2

Therefore, the 2 numbers ⇢  The first number is 8 and the second number is 2.

问题 2：给定两个差为 50 且和为 100 的数。找出这 2 个数。

解决方案：

Step-by-step explanation:

Since the 2 numbers are unknown, assume them to be two natural numbers  x and y

Given: Difference of x and y=50

Therefore,

x-y = 50  ⇢  (1)

Given: Sum of x and y=100

which can be written as

x+y = 100  ⇢  (2)

Now it can be observed that 2 equations are formed and 2 unknown variables are obtained, which implies that on performing arithmetic operations on these 2 equations the value of the unknown variables can be obtained.

Hence, on Adding equation (1) & equation (2),

2x = 150

which implies x = 75

Since value of x is known put x=75 in equation (1) and get y=25

Therefore, the 2 numbers ⇢ The first number is 75 and the second number is 25.

问题 3：给定两个差为 100 且和为 30 的整数，找出这 2 个数。

解决方案：

Step-by-step explanation:

Since the 2 numbers are unknown, assume them to be two natural numbers  x and y

Given: Difference of x and y=100

Therefore, 

x-y = 100  ⇢  (1)

Given: Sum of x and y = 30

which can be written as

x+y = 30  ⇢  (2)

Now it can be observed that 2 equations are formed and 2 unknown variables are obtained, which implies that on performing arithmetic operations on these 2 equations the value of the unknown variables can be obtained.

Hence, on Adding equation (1) & equation (2),

2x = 130

which implies x = 65

Since value of x is known put x = 65 in equation (1) and get y = -35

Therefore, the 2 numbers ⇢ The first number is 65 and the second number is -35.