两个数字的和是 18，它们的差是 8。找出这些数字

引入了一个系统来定义从负无穷到正无穷的数字。该系统被称为数字系统。数系很容易在数轴上表示，整数、整数、自然数都可以在数轴上定义。数轴包含正数、负数和零。

方程是一种数学语句，它用“=”符号连接两个相等值的代数表达式。例如：在等式 3x+2 = 5 中，3x+ 2 是左侧表达式，5 是与“=”符号连接的右侧表达式。

主要有3种方程：

• 线性方程
• 二次方程
• 多项式方程

在这里，我们将研究线性方程组。

一个变量的线性方程是写成 ax + b = 0 的方程，其中 a 和 b 是两个整数，x 是一个变量，并且只有一个解。例如，3x+2=5 是一个只有一个变量的线性方程。因此，这个方程只有一个解，即 x = 3/11。另一方面，两个变量的线性方程有两个解。

A one-variable linear equation is one with a maximum of one variable of order one. The formula is ax + b = 0, using x as the variable.

这个方程只有一个解。这里有一些例子：

• 4x = 8
• 5x + 10 = -20
• 1 + 6x = 11

一个变量中的线性方程以标准形式写成：

ax + b = 0

这里，

• 数字“a”和“b”是实数。
• 'a' 和 'b' 都不等于 0。

求解一个变量中的线性方程

求解只有一个变量的方程的步骤如下：

步骤 1：如果有任何分数，请使用 LCM 将其删除。

第 2 步：等式两边都应该简化。

第 3 步：从方程中删除变量。

第 4 步：确保您的回答是正确的。

问题陈述：哪两个数的和为 18，差为 8？

解决方案：

Let both numbers be first and second.

According to the problem statement:

first + second = 18 (Consider this as 1st equation)
first – second = 8  (Consider this as 2nd equation)

Add both equations:

first + second + first – second = 18 + 8
2 * first = 26
first = 26 / 2
first = 13

So from this we get first = 13, put this value in any equation i.e.

first + second = 18 (Put the value of first in this equation)
13 + second = 18
second = 18 – 13
second = 5

So, the numbers are 13 and 5.

If we consider the case i.e. second – first = 8, then the solution will be same and the first number will become 5 and second number will become 13.

示例问题

问题1：三个数之和是33，这三个数的前两个数之和是19。任务是找到第三个数。

解决方案：

Let the numbers be first, second and third.

According to the problem statement:
first + second + third = 33 (Consider this as 1st equation)
first + second = 19  (Consider this as 2nd equation)

So, put the value of 2nd equation in 1st equation i.e.

first + second +third = 33 (Put the value of first+second in this equation)
19 + third = 33
third = 33 – 19
third = 14

So, the third number is 14.

问题2：哪两个数的和为30，差为8？

解决方案：

Let the both numbers be first and second.

According to the problem statement:

first + second = 30(Consider this as 1st equation)
first – second = 8  (Consider this as 2nd equation)

Add both equations:

first + second + first – second = 30 + 8
2 * first = 38
first = 38 / 2
first = 19

So from this we get first = 19, put this value in any equation i.e.

first + second = 30 (Put the value of first in this equation)
19 + second = 30
second = 30 – 19
second = 11

So, the numbers are 19 and 11.

If we consider the case i.e. second – first = 8, then the solution will be same and the first number will become 11 and second number will become 19.