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

Toán Lớp 8: Cho biểu thức : A= (2 căn x/căn x +3 )+(căn x +1/căn x -3)+ (3-11 nhân căn x/ 9 -x) Rút gọn A hơi rắc rối tại em dùng laptop mn giúp e

Toán Lớp 8: Cho biểu thức :
A= (2 căn x/căn x +3 )+(căn x +1/căn x -3)+ (3-11 nhân căn x/ 9 -x)
Rút gọn A
hơi rắc rối tại em dùng laptop mn giúp e vs ạ

Comments ( 2 )

  1. Giải đáp:
    A = (2sqrtx)/(sqrtx+3) + (sqrtx+1)/(sqrtx-3) + (3-11sqrtx)/(9-x)
    = (2sqrtx)/(sqrtx+3) + (sqrtx+1)/(sqrtx-3) + (3-11sqrtx)/((3-sqrtx)(3+sqrtx))
    = (2sqrtx)/(sqrtx+3) + (sqrtx+1)/(sqrtx-3) – (3-1sqrtx)/((sqrtx-3)(sqrtx+3))
    = (2sqrtx(sqrtx-3)+(sqrtx+3)(sqrtx+1)-(3-11sqrtx))/((sqrtx-3)(sqrtx+3))
    = (2x-6sqrtx+x+sqrtx+3sqrtx+3-3+11sqrtx)/((sqrtx-3)(sqrtx+3))
    = (3x+9sqrtx)/((sqrtx-3)(sqrtx+3))
    = (3sqrtx(sqrtx+3))/((sqrtx-3)(sqrtx+3))
    = (3sqrtx)/(sqrtx-3)

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