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一个步骤的不等式复习

复习解一个步骤的不等式, 并尝试练习解一些题目。

不等式符号

符号意思
is greater than大于
start underline, is greater than, end underline大于或等于
is less than小于
start underline, is less than, end underline小于或等于

用加法和减法求解不等式

解不等式,就像解方程:我们要分离变量。
例 1: x, plus, 7, is greater than, 4
为了分离 x,可以从不等式的两边 start color #11accd, start text, 减, 去, space, end text, 7, end color #11accd
x, plus, 7, start color #11accd, minus, 7, end color #11accd, is greater than, 4, start color #11accd, minus, 7, end color #11accd
现在我们把式子化简。
x, is greater than, minus, 3
例 2:z, minus, 11, space, start underline, is less than, end underline, 5
要分离 z,可在式子两边 start color #1fab54, start text, 加, 上, space, end text, 11, end color #1fab54
z, minus, 11, start color #1fab54, plus, 11, end color #1fab54, space, start underline, is less than, end underline, 5, start color #1fab54, plus, 11, end color #1fab54
现在我们把式子化简。
z, space, start underline, is less than, end underline, 16
想更多了解一步不等式?点击 这个视频

第1组练习

问题1A
  • 当前
求解 x
答案必须化简。
x, minus, 8, is less than, minus, 1

用乘除法解不等式

目的同样是分离变量。但是当乘以或除以一个负数时情况有一点不同。仔细看看有什么不同!
例 1: 10, x, is less than, minus, 3
要分离 x,把式子两边除以 10
start fraction, 10, x, divided by, 10, end fraction, is less than, start fraction, minus, 3, divided by, 10, end fraction
现在我们把式子化简。
x, is less than, minus, start fraction, 3, divided by, 10, end fraction
例 2:start fraction, y, divided by, minus, 6, end fraction, space, start underline, is greater than, end underline, space, 4
分离 y,在两边同乘以 minus, 6
left parenthesis, start fraction, y, divided by, minus, 6, end fraction, right parenthesis, times, minus, 6, space, start underline, is greater than, end underline, space, 4, times, minus, 6
现在我们把式子化简。
y, space, start underline, is less than, end underline, minus, 24

练习2

问题2A
  • 当前
求解 x
答案必须化简。
2, x, is less than, 15

想再多练习一些?点击 练习

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