Toán Lớp 8: 1. a,(x²/2-6x)² b,(x+y/2)² c,(3x/2-y/4)²

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Toán Lớp 8: 1. a,(x²/2-6x)² b,(x+y/2)² c,(3x/2-y/4)²

Việt Hòa Tháng Hai 13, 2023 Toán học 1 Comment 0 views

Toán Lớp 8: 1.
a,(x²/2-6x)² b,(x+y/2)²
c,(3x/2-y/4)² d,(-4a/3-b/3)²
e,(-x/5+2y)² f,(x+2y)²
g,(3x-4y)² h,(5+y)²
2.
a,2x(x-5) – (x-2)² – (x+3) (x-3) b,(x+1)² + 3(x-5) (x+5) – (2x-1)²
c,(x²+2)² – (x+2) (x-2) (x²+4) d,(x+2) (x-2) – 1/2 (6-8x)²+17

lantrungbach · Answer

Giải đáp:+Lời giải và giải thích chi tiết:   1.   a) (x&sup2;/2 - 6x)&sup2;   = (x&sup2;/2)&sup2; - 2(x&sup2;/2)(6x) +36x&sup2;   = x^4/4 - 12x&sup3;/2 + 36x&sup2;   b) (x+y/2)&sup2;   = x&sup2;+ 2.x.y/2 + (y/2)&sup2;   c) (3x/2 - y/4)&sup2;   =(3x/2)&sup2; - 2(3x/2)(y/4) + (y/4)&sup2;   =9x/4 - 6xy/8 +y&sup2;/16   d) (-4a/3-b/3)&sup2;   =(-4a/3)&sup2;-2(-4a/3)(b/3)+(b/3)&sup2;   =16a&sup2;/9 + 8ab/9 +b&sup2;/9   e) (-x/5+2y)&sup2;   = (-x/5)&sup2;+2(-x/5)(2y) +(2y)&sup2;   =x/25-4xy/5+4y    f,(x+2y)&sup2;     =x&sup2;+4xy+4y    g,(3x-4y)&sup2;   =9x-24xy+16y   h,(5+y)&sup2;   =25+10y+y&sup2;    2. a,2x(x-5) - (x-2)&sup2; - (x+3) (x-3)      =2x&sup2;-10x-x&sup2;+4x-4-x&sup2;+9     = -6x + 5     b,(x+1)&sup2; + 3(x-5) (x+5) - (2x-1)&sup2;      = x&sup2;+2x+1 + 3x&sup2;-75 - 4x&sup2;+4x-1     =6x-75     c,(x&sup2;+2)&sup2; - (x+2) (x-2) (x&sup2;+4)     =x^4 + 2x&sup2;4 + 4 - (x&sup2; - 4) (x&sup2; + 4)     =x^4 + 8x&sup2; + 4 - x^4 -16     =8x&sup2;-16     =8(x&sup2;-2)     d,(x+2) (x-2) - 1/2 (6-8x)&sup2;+17     =x&sup2;-4 - 1/2(36-96x+64x)+17     =x&sup2; +13 -18 +48x - 32x     =x&sup2; - 5 + 16