9x^2-xy+1/36y^2
a^2+2ab+b^2+(a+b)^3
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
9x^2-xy+1/36y^2
2x^8-12x^4+18
x^2-2xy+y^2-a^2
x^2+2xy+y^2-1
(a+b+c)^3-a^3-b^3-c^3
Bạn nào giúp mình nhé ! Mình đang cần gấp, mình sẽ tích cho bạn.^^
Bài 1: Phân tích đa thức thành nhân tử: a) 4y3 + 16y2 + 16y b) 8x2-48x+6xy-36y c) 8x2-48x-6xy+36y d) a2 –2ab+b2 –4 e) 4–x2 –4xy–4y2 f) 8a2 –16a+8ax–16x g) 16–4x2 +8xy–4y2 h) –4x2 –16xy–16y2 Bài 2: Tìm x, biết: a) x3 – 6x2 + 9x = 0 b) 5x(x–6)+3x–18=0 c) 5x(x – 6) – 18 + 3x = 0 d) 5x(x – 6) – 3x + 18 = 0 e) (2x – 3)2 = (5 – x)2 f) (2x + 1)2 = (3x – 2)2 g) 16(2x–3)=-25x2 (3–2x)
b: \(8x^2-48x+6xy-36y\)
\(=8x\left(x-6\right)+6y\left(x-6\right)\)
\(=2\left(x-6\right)\left(4x+3y\right)\)
d: \(a^2-2ab+b^2-4\)
\(=\left(a-b\right)^2-4\)
\(=\left(a-b-2\right)\left(a-b+2\right)\)
phân tích đa thức thành nhân tử:
áp dụng 7 hàng đẳng thức
a, x^6-y^6
b,10ab+0,25a^2+100b^2
c, 9x^2-xy+1/36y^2
a) \(x^6-y^6\)
\(=\left(x^3\right)^2-\left(y^3\right)^2\)
\(=\left(x^3-y^3\right)\left(x^3+y^3\right)\)
\(=\left(x-y\right)\left(x^2+xy+y^2\right)\left(x+y\right)\left(x^2-xy+y^2\right)\)
b) \(10ab+0,25a^2+100b^2\)
\(=\left(0,5a\right)^2+2\cdot0,5a\cdot10b+\left(10b\right)^2\)
\(=\left(0,5a+10b\right)^2\)
c) \(9x^2-xy+\frac{1}{36}y^2\)
\(=\left(3x\right)^2-2\cdot3x\cdot\frac{1}{6}y+\left(\frac{1}{6}y\right)^2\)
\(=\left(3x-\frac{1}{6}y\right)^2\)
a) 9x2 - xy + 1/36y2
b) x3 + y3 + z3 - 3xy
c) x3 - xy + x - y
d) 3x2 + 6xy + 3y2 - 3z2
1) X^2 +xy - 8x - 8y
2) 9x^2- 6x + 1 - 36y^2
3) a^2 - b^2 - 12a + 12b
4) x^2 - 2xy + 8x - 16y
5) x^2 - 9y^2 + 5x + 15y
Mấy bạn giúp mình bài này nha
1) x2 + xy-8x-8y
= x.(x+y) -8.(x+y)
= (x+y).(x-8)
2) 9x2 -6x + 1 -36y2
=(3x-1)2 -(6y)2
=(3x-1-6y)(3x-1+6y)
3)a2 - b2 -12a+12b
= (a-b)(a+b)-12.(a-b)
=(a-b).(a+b-12)
4)x2 -2xy+8x-16y
=x.(x-2y)+8.(x-2y)
=(x-2y).(x+8)
5) x2 -9y2 +5x+15y
=(x-3y)(x+3y)+5.(x+3y)
= (x+3y).(x-3y+5)
\(1,x^2+xy-8x-8y=x\left(x+y\right)-8\left(x+y\right)=\left(x-8\right)\left(x+y\right)\)\(3,a^2-b^2-12a+12b=\left(a-b\right)\left(a+b\right)-12\left(a-b\right)=\left(a-b\right)\left(a+b-12\right)\)\(4,x^2-2xy+8x-16y=x\left(x-2y\right)+8\left(x-2y\right)=\left(x+8\right)\left(x-2y\right)\)\(5,x^2-9y^2+5x+15y=\left(x-3y\right)\left(x+3y\right)+5\left(x+3y\right)=\left(x+3y\right)\left(x-3y+5\right)\)
Thực hiện phép tính
a, (3-xy^2) ^2-(2+xy^2) ^2
b, 9x^2-(3x-4) ^2
c, (a-b^2). (a+b^2)
d, (a^2+2a+3). (a^2+2a-3)
a) \(\left(3-xy^2\right)^2-\left(2+xy^2\right)^2\)
\(=\left(3-xy^2-2-xy^2\right)\left(3-xy^2+2+xy^2\right)\)
\(=\left(1-2xy^2\right).5=5-10xy^2\)
b) \(9x^2-\left(3x-4\right)^2\)
\(=\left(3x-3x+4\right)\left(3x+3x-4\right)\)
\(=4.\left(6x-4\right)=24x-16\)
c) \(\left(a-b^2\right)\left(a+b^2\right)\)
\(=a^2-b^{^4}\)
d) \(\left(a^2+2a+3\right)\left(a^2+2a-3\right)\)
\(=\left[\left(a^2+2a\right)^2\right]-3^2\)
\(=a^4+4a^3+4a^2-9\)
1.Rút gọn biểu thức:
(2x+3)2+(2x-3)2+2(2x+3)(2x-3)
2.Thực hiện phép tính:
a.(x2+xy+y2)(x-y)+(x2-xy+y2)(x+y)
b.(2a-b).(4a2+2ab+b2)
c.13 x.(3-x)-12 (x+1)
d.(2x-1)(x+12 )(x2+14 )
e.(2a-b).(4a2+2ab+b2)
Bài 1:
\(\left(2x+3\right)^2+\left(2x-3\right)^2+2\left(2x+3\right)\left(2x-3\right)\)
\(=\left(2x+3+2x-3\right)^2=\left(4x\right)^2=16x^2\)
Bài 2:
a, \(\left(x^2+xy+y^2\right)\left(x-y\right)+\left(x^2-xy+y^2\right)\left(x+y\right)\)
\(=x^3-y^3+x^3+y^3=2x^3\)
b, \(\left(2a-b\right)\left(4a^2+2ab+b^2\right)\)
\(=\left(2a\right)^3-b^3=8a^3-b^3\)
c, \(13x\left(3-x\right)-12\left(x+1\right)\)
\(=39x-13x^2-12x-12=-13x^2-27x-12\)
d, \(\left(2x-1\right)\left(x+12\right)\left(x^2+14\right)\)
\(=\left(2x^2+24x-x-12\right)\left(x^2+14\right)\)
\(=2x^4+23x^3-12x^2+28x^2+322x-168\)
\(=2x^4+23x^3+16x^2+322x-168\)
e, Giống câu b
Chúc bạn học tốt!!!
Cho 2 số thực dương a và b thỏa mãn
a, sin (2 - 2ab) - sin (a + b) = 2a + a+ b - 2
Tìm Min của S = a + 2b
b, cos (x + y + 1) + 3 = cos(3xy) + 9xy - 3x - 3y
Tìm Min của S = xy + 2x