triển khai các tích sau
a)( 1/2m+3)3
b)[2(m+1/2)]
c)(2 căn x+1)2 vớix>0
d)(+1/4)2
giúp mình với mình cần gấp
triển khai các tích sau
a)( 1/2m+3)3
b)[2(m+1/2)]
c)(2 căn x+1)2 vớix>0
d)(2*căn bậc hai(2)+1/4)2giúp mình v
a) \(\left(\dfrac{1}{2}m+3\right)^3=\dfrac{m^3}{8}+\dfrac{9m^2}{4}+\dfrac{27m}{2}+9\)
b) \(2\left(m+\dfrac{1}{2}\right)=2m+1\)
c) \(\left(2\sqrt{x}+1\right)^2=4x+4\sqrt{x}+1\)
d) \(\left(2\sqrt{2}+\dfrac{1}{4}\right)^2=8+\sqrt{2}+\dfrac{1}{16}=\dfrac{129}{16}+\sqrt{2}\)
chi tiết câu c
c) \(\left(2\sqrt{x}+1\right)^2=\left(2\sqrt{x}\right)^2+2\cdot2\sqrt{x}\cdot1+1^2=4x+4\sqrt{x}+1\)
a) \(\left(\dfrac{1}{2}m+3\right)^3\)
\(=\left(\dfrac{1}{2}m\right)^3+3\cdot\left(\dfrac{1}{2}m\right)^2\cdot3+3\cdot\dfrac{1}{2}m\cdot3^2+3^3\)
\(=\dfrac{1}{8}m^3+\dfrac{9}{4}m^2+\dfrac{27}{2}m+27\)
c) Ta có: \(\left(2\sqrt{x}+1\right)^2\)
\(=\left(2\sqrt{x}\right)^2+2\cdot2\sqrt{x}\cdot1+1^2\)
\(=4x+4\sqrt{x}+1\)
Bài 9: Tìm x, biết:
a)|-2x+1,5|=1/4
b)3/2-|1 1/4+3x|=1/4
c)|4x-1| - |3x-1/2|=0
d)|x-1|-2x=1/2
Giúp mình với mình đang cần gấp
\(|-2x+1,5|=\dfrac{1}{4}\Rightarrow-2x+1,5=\pm\dfrac{1}{4}\)
\(-2x+1,5=\dfrac{1}{4}\Rightarrow-2x=1,5-0,25\Rightarrow-2x=1,25\Rightarrow x=1,25:\left(-2\right)\Rightarrow x=...\)
\(-2x+1,5=-\dfrac{1}{4}\Rightarrow-2x=-0,25-1,5\Rightarrow-2x=1,75\Rightarrow x=1,75:\left(-2\right)\Rightarrow x=...\)
\(\dfrac{3}{2}-|1.\dfrac{1}{4}+3x|=\dfrac{1}{4}\Rightarrow|1.\dfrac{1}{4}+3x|=\dfrac{3}{2}-\dfrac{1}{4}\Rightarrow|1.\dfrac{1}{4}+3x|=\dfrac{5}{4}\)
\(\Rightarrow1.\dfrac{1}{4}+3x=\pm\dfrac{5}{4}\)
\(1.\dfrac{1}{4}+3x=\dfrac{5}{4}\Rightarrow\dfrac{1}{4}+3x=\dfrac{5}{4}\Rightarrow3x=\dfrac{5}{4}-\dfrac{1}{4}\Rightarrow3x=1\Rightarrow x=3\)
\(1.\dfrac{1}{4}+3x=-\dfrac{5}{4}\Rightarrow\dfrac{1}{4}+3x=-\dfrac{5}{4}\Rightarrow3x=-\dfrac{5}{4}-\dfrac{1}{4}\Rightarrow3x=-\dfrac{3}{2}x=...\)
a: ta có: \(\left|-2x+\dfrac{3}{2}\right|=\dfrac{1}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}-2x+\dfrac{3}{2}=\dfrac{1}{4}\\-2x+\dfrac{3}{2}=-\dfrac{1}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}-2x=-\dfrac{5}{4}\\-2x=-\dfrac{7}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{8}\\x=\dfrac{7}{8}\end{matrix}\right.\)
b: Ta có: \(\dfrac{3}{2}-\left|\dfrac{5}{4}+3x\right|=\dfrac{1}{4}\)
\(\Leftrightarrow\left|3x+\dfrac{5}{4}\right|=\dfrac{5}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}3x+\dfrac{5}{4}=\dfrac{5}{4}\\3x+\dfrac{5}{4}=-\dfrac{5}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=0\\3x=-\dfrac{5}{2}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{5}{6}\end{matrix}\right.\)
a, x-1/4=5/3
b, x:2/3=1/2
giúp mình với ạ!!
Tìm x:
a,50%x - 0,2 + x =4/5
b,(x - 3/4) : 1/2 + 3/2 =25/2
Giúp mình với!! mình cần gấp!! Cảm ơn
\(a,50\%x-0,2+x=\dfrac{4}{5}\)
\(\Leftrightarrow\dfrac{1}{2}x-0,2+x=\dfrac{4}{5}\)
\(\Leftrightarrow\dfrac{1}{2}x+x=\dfrac{4}{5}+0,2\)
\(\Leftrightarrow\dfrac{3}{2}x=\dfrac{4}{5}+\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{3}{2}x=1\)
\(\Leftrightarrow x=\dfrac{2}{3}\)
\(b,\left(x-\dfrac{3}{4}\right):\dfrac{1}{2}+\dfrac{3}{2}=\dfrac{25}{2}\)
\(\Leftrightarrow\left(x-\dfrac{3}{4}\right).2=\dfrac{25}{2}-\dfrac{3}{2}\)
\(\Leftrightarrow\left(x-\dfrac{3}{4}\right).2=\dfrac{22}{2}\)
\(\Leftrightarrow x-\dfrac{3}{4}=11:2\)
\(\Leftrightarrow x=\dfrac{11}{2}+\dfrac{3}{4}\)
\(\Leftrightarrow x=\dfrac{25}{4}\)
1. Tìm x N sao cho:
a) (x - 140) : 7 = -
. 3
b) .
=
:
c) (x + 2) . (x - 4) = 0
d) -
= 2 .
2. Tìm x N sao cho:
a) 9 : (x + 2)
b) (x + 17) : (x + 3)
Giúp mình với, mình cân gấp!
Câu 2:
a: \(\Leftrightarrow x+2\in\left\{3;9\right\}\)
hay \(x\in\left\{1;7\right\}\)
c) (x2 + 1). (x + 2) > 0
d) (x + 4). (x – 3) < 0
e) ( x2 + 2). (x2 + 5) < 0
f) (x + 6). (x – 4) > 0
Giúp mình với, mình cần gấp ạ
Hai bài bị trùng nhau nên các bạn nhìn ảnh hay văn bản đều như nhau ạ
c: =>x+2>0
hay x>-2
d: =>-4<=x<=3
e: =>\(x\in\varnothing\)
f: \(\Leftrightarrow\left[{}\begin{matrix}x>4\\x< -6\end{matrix}\right.\)
rút gọn các biểu thức
A=(x+y)^2+4xy
B=(6x-2)^2+4(3x-1)(2+y)+(y+2)^2
C=(x-y)^2+2(x^2-y^2)+(x+y)^2
giúp mình với nha mình đang cần gấp
1) \(A=\left(x+y\right)^2+4xy=x^2+2xy+y^2+4xy=x^2+6xy+y^2\)
2) \(B=\left(6x-2\right)^2+4\left(3x-1\right)\left(2+y\right)+\left(y+2\right)^2\)
\(=\left(6x-2\right)^2+2\left(6x-2\right)\left(y+2\right)+\left(y+2\right)^2\)
\(=\left(6x-2+y+2\right)^2=\left(6x+y\right)^2=36x^2+12xy+y^2\)
3) \(C=\left(x-y\right)^2+2\left(x^2-y^2\right)+\left(x+y\right)^2\)
\(=\left(x-y\right)^2+2\left(x-y\right)\left(x+y\right)+\left(x+y\right)^2\)
\(=\left(x-y+x+y\right)^2=\left(2x\right)^2=4x^2\)
A. (Theo mình là -4xy thì mới rút gọn được)
B = (6x + y)^2
C = (2x)^2 = 4x^2
phân tích đa thức thành nhân tử
x2 - 6x + 9
9y2 + 12xy + 4x2
1/25 x2 - 64y2
x3 - 8y3
(4x - 3)2 - (x+1)2
Giúp mình với mình đang cần gấp
1. (x-3)2
2. (3y+2x)2
3. (1/5x-8y)(1/5x+8y)
4. (x-2y)(x2+2xy+4y2)
5. (4x-3-x-1)(4x-3+x+1)
(3x-4)(5x-2)
Bài 1 khai triển các hằng đẳng thức
K) 4.x^2=
L) 1/9x^2 -25/16 y ^2
M)1/4x^2-4x^2
N) 4 /49 -4x^2
O) (x-3) (x+3)
P (x +4) (x -4 )
Mik cần gấp giúp mik vs
m) \(\dfrac{1}{4}x^2-4x^2=\left(\dfrac{1}{2}x-2x\right)\left(\dfrac{1}{2}x+2x\right)\)
n) \(\dfrac{4}{49}-4x^2=\left(\dfrac{2}{7}-2x\right)\left(\dfrac{2}{7}+2x\right)\)
o) \(\left(x-3\right)\left(x+3\right)=x^2-9\)