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

Toán Lớp 8: 1.Tính: a. (-8x ³y + 2y^4) (3xy ³ – 2x^4+7y^4) b. 3x(2x+5) + (6x-1) (2 – x)+2 c. x ² + (3x+1) (5x – 3) – (1 – 4x) ² d. (2x-1) (3x+2) (3

Home/ Toán Lớp 8: 1.Tính: a. (-8x ³y + 2y^4) (3xy ³ – 2x^4+7y^4) b. 3x(2x+5) + (6x-1) (2 – x)+2 c. x ² + (3x+1) (5x – 3) – (1 – 4x) ² d. (2x-1) (3x+2) (3

Toán Lớp 8: 1.Tính: a. (-8x ³y + 2y^4) (3xy ³ – 2x^4+7y^4) b. 3x(2x+5) + (6x-1) (2 – x)+2 c. x ² + (3x+1) (5x – 3) – (1 – 4x) ² d. (2x-1) (3x+2) (3

Tháng Một 15, 2023 Toán học 2 Comments 0 views

Toán Lớp 8: 1.Tính:
a. (-8x ³y + 2y^4) (3xy ³ – 2x^4+7y^4)
b. 3x(2x+5) + (6x-1) (2 – x)+2
c. x ² + (3x+1) (5x – 3) – (1 – 4x) ²
d. (2x-1) (3x+2) (3 – x)

Comments ( 2 )

  1. thucquyenlan
    thucquyenlan
    15 Tháng Một, 2023 at 11:45 chiều
    Reply
    Giải đáp:
     $1):$
    $a) (-8x³y+2y^4).(3xy³-2x^4+7y^4)$
    $= (-8x³y).(3xy³-2x^4+7y^4)+2y^4.(3xy³-2x^4+7y^4)$
    $= -24x^4y^4+16x^7y-56x^3y^5+6xy^7-4x^4y^4+14y^8$
    $= -28x^4y^4+16x^7y-56x^3y^5+6xy^7+14y^8$
    $b) 3x.(2x+5)+(6x-1).(2-x)+2$
    $= 6x²+15x+12x-6x²-2+x+2$
    $= (6x²-6x²)+(15x+12x+x)+(2-2)$
    $= 28x$
    $c) x²+(3x+1).(5x-3)-(1-4x)²$
    $= x²+15x²-9x+5x-3-1+8x-16x²$
    $= (15x²+x²-16x²)+(5x+8x-9x)-(3+1)$
    $= 4x-4$
    $d) (2x-1).(3x+2).(3-x)$
    $= (6x²+4x-3x-2).(3-x)$
    $= (6x²+x-2).(3-x)$
    $= 3.(6x²+x-2)-x.(6x²+x-2)$
    $= 18x²+3x-6-6x³-x²+2x$
    $= (18x²-x²)+(3x+2x)-6x³-6$
    $= -6x³+17x²+5x-6$
    $@Pluto$

  2. diemmyhoa
    diemmyhoa
    15 Tháng Một, 2023 at 11:45 chiều
    Reply
    Vote mk 5 sao nhé^^
     

    toan-lop-8-1-tinh-a-8-y-2y-4-3y-2-4-7y-4-b-3-2-5-6-1-2-2-c-3-1-5-3-1-4-d-2-1-3-2-3

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

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