Question

Rút gọn biểu thức sau: P=(5x-1)+2(1-5x)(4+5x)+(5x+4)²

Answer 1

DỀ sai ròi kìa 

P = ( 5x- 1) ^2 + 2 ( 1 - 5x) .(4+5x) + (5x+4)^2

    = (5x- 1 )^2 - 2 ( 5x- 1).(5x+4) + (5x+4)^2

    =  (5x - 1 - 5x - 4) ^2 = ( - 5)^2 = 25

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Answer 2

để bn í ghi đúng mừ

Answer 3

 P = (5x - 1) + [(-2).(-1).(1-5x).(4+5x)] + (5x+4)^2
= (5x - 1).[(-1)-2.(-1).(4+5x)] + (25x^2+40x+16)
= [(5x - 1).(10x + 7)] + (25x^2+40x+16)
= 50x^2 +35x - 10x - 7 + 25x^2+40x+16
= 75x^2 + 65x -9