共50条信息
已知\(\dfrac{xy}{x+y}={2}\),\(\dfrac{xz}{x+z}={3}\),\(\dfrac{yz}{y+z}={4}\),求\(7x+5y-2z\)的值.
已知\(a\)与\(b\)互为相反数,\(c\)与\(d\)互为倒数,\(x\)的绝对值等于\(2\),则\({a+b}-{cdx}\)的值为_________.
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