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222-9+11+12:2*14+14 = ? ( )

Toán Lớp 9: cho bieu thuc p=2-can x /3can x tim x de p co gia tri nguyen khong vuot qua 1

Toán Lớp 9: cho bieu thuc p=2-can x /3can x
tim x de p co gia tri nguyen khong vuot qua 1

Comments ( 2 )

  1. (2-sqrtx)/sqrtx(x>0) 
    vì P<=1
    =>2-sqrtx<=1
    <=>-sqrtx<=-1
    <=>sqrtx>=1
    <=>x<=1(vì x>0)
    =>0<x<=1 thì P<=1

  2. #tnvt
    P=\frac{2-\sqrt{x}}{3\sqrt{x}}(x>0)
    P<=1
    =>\frac{2-\sqrt{x}}{3\sqrt{x}}<=1
    <=>\frac{2-\sqrt{x}}{3\sqrt{x}}-1<=0
    <=>\frac{2-\sqrt{x}-3\sqrt{x}}{3\sqrt{x}}<=0
    <=>\frac{2-4\sqrt{x}}{3\sqrt{x}}<=0
    Mà 3\sqrt{x}>x∀x>0
    =>2-4\sqrt{x}<=0
    <=>4\sqrt{x}>=2
    <=>\sqrt{x}>=1/2
    <=>x>=1/4
    Vậy với x>=1/4 thì P<=1

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222-9+11+12:2*14+14 = ? ( )