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

Toán Lớp 8: a) x2 + 6xy + 9y2 b) 4a4 – 4a2b2 + b4 c) x6 + y2 – 2x3y d)(x + y)3 – (x – y )3 e)25×4 – 10x2y2 + y4 f)x3 + 9x2y+ 27xy2 + 27y3 g) 16×2 –

Home/ Toán Lớp 8: a) x2 + 6xy + 9y2 b) 4a4 – 4a2b2 + b4 c) x6 + y2 – 2x3y d)(x + y)3 – (x – y )3 e)25×4 – 10x2y2 + y4 f)x3 + 9x2y+ 27xy2 + 27y3 g) 16×2 –

Toán Lớp 8: a) x2 + 6xy + 9y2 b) 4a4 – 4a2b2 + b4 c) x6 + y2 – 2x3y d)(x + y)3 – (x – y )3 e)25×4 – 10x2y2 + y4 f)x3 + 9x2y+ 27xy2 + 27y3 g) 16×2 –

Tháng Sáu 16, 2022 Toán học 1 Comment 0 views

Toán Lớp 8: a) x2 + 6xy + 9y2 b) 4a4 – 4a2b2 + b4 c) x6 + y2 – 2x3y d)(x + y)3 – (x – y )3
e)25×4 – 10x2y2 + y4 f)x3 + 9x2y+ 27xy2 + 27y3 g) 16×2 – 9 (x + y)2 h)(a – b)2 – 1
i)a6 –b6 k)– a2 – 2a – 1 e)27b3 – 8a3
nhanhhhh nhaaaa

Comments ( 1 )

  1. maianhtuanh
    maianhtuanh
    16 Tháng Sáu, 2022 at 5:49 sáng
    Reply
    a) x^{2}+6xy+9y^{2}=x^{2}+2·x·3y+(3y)^{2}=(x+3y)^{2}     (áp dụng hđt)
    b) 4a^{4}-4a^{2}b^{2}+b^{4}=(2a^{2})^{2}-2·2a^{2}·b^{2}+(b^{2})^{2}=(2a^{2}-b^{2})^{2}     (áp dụng hđt)
    c) x^6+y^2–2x^3y=(x^3)^2-2·x^3·y+y^2=(x^3-y)^2     (áp dụng hđt)
    d) (x+y)^3–(x–y)^3     (áp dụng hđt)
    =[x+y-(x-y)][(x+y)^2+(x+y)(x-y)+(x-y)^2]
    =(x+y-x+y)(x^2+2xy+y^2+x^2-y^2+x^2-2xy+y^2)
    =2y(3x^2+y^2)
    e) 25x^4–10x^2y^2+y^4=(5x^2)^2-2·5x^2·y^2+(y^2)^2=(5x^2-y^2)^2     (áp dụng hđt)
    f) x^3+9x^2y+27xy^2+27y^3=x^3+3·x^2·3y+3·x·(3y)^2+(3y)^3=(x+3y)^3     (áp dụng hđt)
    g) 16x^2–9(x+y)^2
    =(4x)^2-[3(x+y)]^2
    =(4x)^2-(3x+3y)^2
    =[4x-(3x+3y)][4x+(3x+3y)]
    =(4x-3x-3y)(4x+3x+3y)
    =(x-3y)(7x+3y)
    h) (a–b)^2–1=(a–b)^2–1^2=(a-b+1)(a-b-1)
    i) a^6–b^6
    =(a^2)^3-(b^2)^3
    =(a^2-b^2)[(a^2)^2+a^2b^2+(b^2)^2]
    =(a+b)(a-b)(a^4+a^2b^2+b^4)
    k) –a^2–2a–1=-(a^2+2·a·1+1^2)=-(a+1)^2
    e) 27b^3–8a^3
    =(3b)^3-(2a)^3
    =(3b-2a)[(3b)^2+3b·2a+(2a)^2]
    =(3b-2a)(9b^2+6ab+4a^2)
    Chúc bạn học tốt, cho mình câu trả lời hay nhất + 5* + cám ơn nha!!!

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

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