Toán Lớp 8: Đề: Phân tích thành nhân tử 44) `12x^2-23xy+10xy^2` 45) `x64-5x^2 y^2+4y^4` 46) `(x^2-8)^2+36` 47) `x^8+x^4+1` 48) `a^2 (b-c)+b^2 (c-a)

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Toán Lớp 8:  Đề: Phân tích thành nhân tử 44) 12x^2-23xy+10xy^2 45) x64-5x^2 y^2+4y^4 46) (x^2-8)^2+36 47) x^8+x^4+1 48) a^2 (b-c)+b^2 (c-a) + c^2 (a-c) 50) ab(a+b)+bc(b+c)+ac(c+a)+3abc 51) 4x^8 +1 Hứa trả đủ 100% e dồn hết điểm vào mấy câu này đấy :(((

haiyemy · Answer

Giải đáp:   44/ 12x&sup2;-23xy+10y&sup2;   =(12x&sup2;-8xy)-(15xy-10y&sup2;)   =4x(3x-2y)- 5xy(3x-2y)   =(3x-2y)(4x-5xy)   =x(3x-2y)(4-5y)      45/ $x^{4}$  -5x&sup2;y&sup2;+$y^{4}$    =($x^{4}$ -4x&sup2;y&sup2;+$y^{4}$) -x&sup2;y&sup2;   =(x&sup2;-y&sup2;)&sup2;-(xy)&sup2;   =(x&sup2;-y&sup2;-xy)(x&sup2;-y&sup2;+xy)      46/ (x&sup2;-8)&sup2;+36   = $x^{4}$ -16x&sup2;+64+36   =$x^{4}$ -16x&sup2;+100   = ($x^{4}$ +20x&sup2;+100)-36x&sup2;   =(x&sup2;+10)&sup2;-(6x)&sup2;   =(x&sup2;+10-6x)(x&sup2;+10+6x)      47/$x^{8}$ +$x^{4}$ +1   =($x^{8}$ +2$x^{4}$ +1)-$x^{4}$   =($x^{4}$+1)&sup2;-(x&sup2;)&sup2;   =($x^{4}$+1-x&sup2;)($x^{4}$+1+x&sup2;)      48/ a&sup2;(b-c)+b&sup2;(c-a)+c&sup2;(a-c)   =a&sup2;(b-c)-b&sup2;(a-c)+c&sup2;(a-c)   = a&sup2;(b-c)-(a-c)(b&sup2;-c&sup2;)   =a&sup2;(b-c)-(a-c)(b-c)(b+c)   =(b-c)[a&sup2;-(a-c)(b+c)]      50/ ab(a+b)+bc(b+c)+ac(c+a)+3abc   =[ab(a+b)+abc]+[bc(b+c)+abc]+[ac(c+a)+abc]   =ab(a+b+c)+bc(a+b+c)+ac(a+b+c)   =(a+b+c)(ab+bc+ca)      51/ $4x^{8}$ +1   =($4x^{8}$ +4$x^{4}$ +1)+$4x^{4}$    = ($2x^{4}$ +1)&sup2;+(2x&sup2;)&sup2;   =($2x^{4}$+1-2x&sup2;)($2x^{4}$+1+2x&sup2;)