Rút gọn:
a) A=(4-5x)2-(3+5x)2
b) B=(3x-1)(1+3x)-(3x+1)2
c) C=(2x+5)3-(2x-5)3-(120x2+49)
d) D=(2a-b+2)3-6(2a-b+2)2+12(2a-b+2)-8-(2a-b)3
Những câu hỏi liên quan
Question Expandand simplify: 1. 8(x+5)-3(2x+7)
2. a(2b+c)+b(3c-2a)
3. 2y(y+5x)+x(3x+4y)
answer , 1. 8(x+5)-3(2x+7)=8x+40-6x+21=2x+61
2. a(2b+c)+b(3c-2a)=2ab+ac+3bc-2ab=ac+3bc=3abc^(2)
3. 2y(y+5x)+x(3x+4y)=2y^(2)+10xy+9x^(2)+4xy=9x^(2)+2y^(2)+14xy
a Explain what he has done wrong.
b work out the correct answer
1.a)4x^4× (4x^4+2x^2)
b) 4x^4 - 2x^2×(3x^3+2x)
c) (3x^3-2y)×(5x^3+3y)
d) (a^3+3ab-b^2) ×(2a-b)
\(a,=16x^8+8x^6\\ b,=4x^4-6x^5-4x^3\\ c,=15x^6+9x^3y-10x^3y-6y^2\\ =15x^6-x^3y-6y^2\\ d,=2a^4-a^3b+6a^2b-3ab^2-3ab^2+b^3\\ =2a^4-a^3b+6a^2b-6ab^2+b^3\)
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Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
Rút gọn biểu thức:
a, 5.(2x-1)2+4.(x-1).(x+3)-2.(5-3x)2
b, (2a2+2a+1).(2a2-2a+1)-(2a2+1)2
c, (9x-1)2+(1-5x)2+2.(9x-1).(1-5x)
RÚT GỌN CÁC BIỂU THỨC SAU 1 CÁCH NHANH NHẤT
A= (6x-2)^2 + (2-5x)^2+2(6x-2)(2-5x)
B= (2a^2+2a+1)(2a^2-2a+1)-(2a^2+1)^2
C=(x+3)(x^2-3x+9)-(54+x^3)
D=(2x+y)(4x^2-2xy+y^2)-(2x-y)(4x^2+2xy+y^2)
E=(a+b)^2-(a-b)^2
A= (6x-2)^2 + (2-5x)^2+2(6x-2)(2-5x)
= (6x-2)^2 +2(6x-2)(2-5x)+ (2-5x)^2
\(=\left(6x-2+2-5x\right)^2=x^2\)
B= (2a^2+2a+1)(2a^2-2a+1)-(2a^2+1)^2
\(=\left(2a^2+1\right)^2-4a^2-\left(2a^2+1\right)^2=4a^2\)
C=(x+3)(x^2-3x+9)-(54+x^3)
\(=\left(x^3+27\right)-54-x^3=27\)
D=(2x+y)(4x^2-2xy+y^2)-(2x-y)(4x^2+2xy+y^2)
\(=\left(2x+y\right)^3-\left(2x-y\right)^3\)
E=(a+b)^2-(a-b)^2
\(=\left(a+b+a-b\right)\left(a+b-a+b\right)=2a.2b=4ab\)
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Secret Personv: thật.CTV lạ z
\(C=\left(x+3\right)\left(x^2-3x+9\right)-\left(54+x^3\right)\)
\(=x^3-27-54-x^3=-81\)
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\(C=\left(x+3\right)\left(x^2-3x+9\right)-\left(54+x^3\right)\)
\(=x^3+27-54-x^3=-27\)
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3x^4 + 3x^2y^2 + 6x^3y - 27x^2
x^4 + x^3 - x^2 + x
2x^5 - 6x^4 - 2a^2x^3 - 6ax^3
x^5 + x^4 + x^3 + x^2 + x + 1
x^3 - 1 + 5x^2 - 5 + 3x - 3
1/4.(a + 1)^2 - 4/9.(a - 2)^2
12a^2b^2 - 3.(a^2b^2)^2
4x^2y^2 - (x^2 + y^2 - a^2)^2
(a + b + c)^2 + (a + b - c)^2 - 4c^2
x^3 - 1 + 5x^2 - 5 + 3x - 3
(3x^3-2x^2+x+2)*(5x^2)
(a^2x^3-5x+3a)*(-2a^3x)
(3x^2+5x-2)(2x^2-4x+3)
(a^4+a^3b+a^2b^2+ab^3+b^4)(a-b)
(3x^3 - 2x^2 + x + 2)(5x^2)
= 15x^5 - 10x^4 + 5x^3 + 10x^2
(3x^2 + 5x - 2)(2x^2 - 4x + 3)
= 3x^4 - 12x^3 + 9x^2 + 10x^3 - 20x^2 + 15x - 4x^2 + 8x - 6
= 6x^4 - 2x^3 - 15x^2 + 23x - 6
rút gọn : a) 5.(2x-1)^2+4(x-1)(x+3)-2(5-3x)^2
b) (2a^2+2a+1)(2a^2-2a+1)=(2a^2+1)^2