使用合适的性质验证以下等式:$(\frac{5}{4}+\frac{-1}{2})+\frac{-3}{2}= \frac{5}{4}+(\frac{-1}{2}+\frac{-3}{2})$
已知
给定的表达式是 $(\frac{5}{4}+\frac{-1}{2})+\frac{-3}{2}= \frac{5}{4}+(\frac{-1}{2}+\frac{-3}{2})$.
需要做的事情
我们需要使用合适的性质验证给定的表达式。
解答
加法的结合律
加法满足结合律。加法的结合律指出
$(a+b)+c = a+(b+c)$
左边 (LHS)
$(\frac{5}{4}+\frac{-1}{2})+\frac{-3}{2}= \frac{(5-2\times 1)}{4} + (\frac{-3}{2})$
$= \frac{3}{4} - \frac{3}{2}$
$= \frac{(3-3\times 2)}{4}$
$= \frac{(3-6)}{4}$
$= \frac{-3}{4}$.
右边 (RHS)
$\frac{5}{4}+(\frac{-1}{2}+\frac{-3}{2}) = \frac{5}{4} +\frac{(-1-3)}{2}$
$=\frac{5}{4} +\frac{-4}{2}$
$= \frac{(5-4\times 2)}{4}$
$= \frac{(5-8)}{4}$
$= \frac{-3}{4}$
$LHS = RHS$
因此,
$(\frac{5}{4}+\frac{-1}{2})+\frac{-3}{2}= \frac{5}{4}+(\frac{-1}{2}+\frac{-3}{2})$ 已被验证。
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