Câu 1 : a ) 3x ( x – 5 ) b ) ( 7x – 1 ) ( 7x + 1 ) c ) x ² + 6x + 9 – y ²

Question

Câu 1 :
a ) 3x ( x – 5 )
b ) ( 7x – 1 ) ( 7x + 1 )
c ) x ² + 6x + 9 – y ²

in progress 0
Athena 4 ngày 2021-12-06T23:44:45+00:00 2 Answers 5 views 0

Answers ( )

    0
    2021-12-06T23:45:53+00:00

    Đáp án:

    `a) 3x(x-5)=3x^2-15x`

    `b) (7x-1)(7x+1)=(7x)^2-1^2=49x^2-1`

    `c) x^2+6x+9-y^2=(x^2+6x+9)-y^2=(x+3)^2-y^2=(x+3-y)(x+3+y)`

    0
    2021-12-06T23:46:24+00:00

    Câu 1 :

    a ) 3x ( x – 5 )

    b ) ( 7x – 1 ) ( 7x + 1 )

    c ) x ² + 6x + 9 – y ²

    TL : 

    a ) 3x ( x – 5 ) 

    = 3x² – 15x

    b ) ( 7x – 1 ) ( 7x + 1 )

    = ( 7x )² – 1²

    c ) x ² + 6x + 9 – y ²

    = ( x² + 6x + 9 ) – y²

    = ( x + 3 ) ² – y² 

    = ( x + 3 – y ) ( x + 3 + y ) 

     

Leave an answer

Browse

35:5x4+1-9:3 = ? ( )