Show that (4x-5)/(2x+1) =2-((7)/(2x+1))?
回答 (1)
2017-02-10 2:19 pm
Method 1 :
L.H.S.
= (4x - 5) / (2x + 1)
= [(4x + 2) - 7] / (2x + 1)
= [2(2x + 1) - 7] / (2x + 1)
= [2(2x + 1) / (2x + 1)] - [7 / (x + 1)]
= 2 - [7 / (2x + 1)]
= R.H.S.
Hence, (4x - 5) / (2x + 1) = 2 - [7 / (2x + 1)]
====
Method 2 :
R.H.S.
= 2 - [7 / (2x + 1)]
= [2(2x + 1) / (2x + 1)] - [7 / (x + 1)]
= [2(2x + 1) - 7] / (2x + 1)
= [4x + 2 - 7] / (2x + 1)
= (4x - 5) / (2x + 1)
= L.H.S.
Hence, (4x - 5) / (2x + 1) = 2 - [7 / (2x + 1)]
L.H.S.
= (4x - 5) / (2x + 1)
= [(4x + 2) - 7] / (2x + 1)
= [2(2x + 1) - 7] / (2x + 1)
= [2(2x + 1) / (2x + 1)] - [7 / (x + 1)]
= 2 - [7 / (2x + 1)]
= R.H.S.
Hence, (4x - 5) / (2x + 1) = 2 - [7 / (2x + 1)]
====
Method 2 :
R.H.S.
= 2 - [7 / (2x + 1)]
= [2(2x + 1) / (2x + 1)] - [7 / (x + 1)]
= [2(2x + 1) - 7] / (2x + 1)
= [4x + 2 - 7] / (2x + 1)
= (4x - 5) / (2x + 1)
= L.H.S.
Hence, (4x - 5) / (2x + 1) = 2 - [7 / (2x + 1)]
收錄日期: 2021-04-18 16:00:49
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