a) 5/(-4) . 16/25 + (-5)/4 . 9/25 b) 38/45 – ( 8/45 – 17/51 – 3/11) b2 a) (14/5 . x – 50) : 2/3 = 51 b) ( 3/5 -x) ³ = -64 c) (2x -1) . ( (-1/3 x + 4)

Question

a) 5/(-4) . 16/25 + (-5)/4 . 9/25
b) 38/45 – ( 8/45 – 17/51 – 3/11)
b2
a) (14/5 . x – 50) : 2/3 = 51
b) ( 3/5 -x) ³ = -64
c) (2x -1) . ( (-1/3 x + 4) =0

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Kaylee 9 phút 2021-09-16T03:35:58+00:00 2 Answers 0 views 0

Answers ( )

    0
    2021-09-16T03:37:24+00:00

    Đáp án:

     

    Giải thích các bước giải:

     a,5/(-4) . 16/25 + (-5)/4 . 9/25

    =5/(-4).(4/5)²+(-5)/4.(3/5)²

    =-4/5+(-9/20)

    =-5/4

    b, 38/45 – ( 8/45 – 17/51 – 3/11)

    = 38/45-8/45+17/51+3/11

    =2/3+20/33

    =14/11

    bài 2

    a, (14/5 . x – 50) : 2/3 = 51

    ⇔(14/5 . x – 50)=51.2/3

    ⇔14/5 . x – 50=34

    ⇔14/5 . x=84

    ⇔x=84:14/5

    ⇔x=30

    vậy x=30

    b, ( 3/5 -x) ³ = -64

    ⇔( 3/5 -x) ³=(-4)³

    ⇔3/5-x=-4

    ⇔x=3/5+4

    ⇔x=23/5

    c, (2x -1) . ( (-1)/3 x + 4) =0

    TH1:

        2x-1=0

    ⇔2x=1

    ⇔x=1/2

    TH2:

      (-1)/3 x + 4 =0

    ⇔ (-1)/3 x=-4

    ⇔x=-4:(-1/3)

    ⇔x=12

    vậy x∈{1/2;12)

    CHÚC BẠN HOK TỐT:)))

    0
    2021-09-16T03:37:44+00:00

    1)

    a)5/(-4) . 16/25 + (-5)/4 . 9/25

    =-5/4×(16/25+9/25)

    =-5/4×25/25=-5/4×1=-5/4

    b)38/45 – ( 8/45 – 17/51 – 3/11)

    =30/45+17/51+3/11=2/3+17/51+3/11

    =34/51+17/51+3/11

    =51/51+3/11=1+3/11=14/11

    2)(14/5×x-50)÷2/3=51

    ⇒14/5×x-50=34

    ⇒14/5×x=84

    ⇒x=30

    b)(3/5 -x) ³ = -64

    ⇒3/5-x=-4

    ⇒x=3/5+4=23/5

    c)(2x -1) . (-1/3 x + 4) =0

     ⇒2x-1=0 hoặc -1/3×x+4=0

     ⇒x=1/2 hoặc x=12

    Vote giùm nha

     

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