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VD
2
HP
9 tháng 12 2021
\(\left(2x^3+x^2+10x+30\right):\left(2x+1\right)\)
\(=2x^3:\left(2x+1\right)+x^2:\left(2x+1\right)+10x:\left(2x+1\right)+30:\left(2x+1\right)\)
\(=2x^3:2x+2x^3:1+x^2:2x+x^2:1+10x:2x+10x:1+30:2x+30:1\)
\(=x^2+2x^3+\dfrac{1}{2}x+x^2+5+10x+15x+30\)
\(=2x^3+2x^2+\dfrac{51}{2}x+35\)
NT
2
5 tháng 10 2021
\(\left(4x-5\right)\left(2x+30\right)-4\left(x+2\right)\left(2x-1\right)+\left(10x+7\right)\)
\(=8x^2+110x-150-8x^2-12x+8+10x+7\)
\(=108x-135\)
NN
3 tháng 8 2020
(3x-1)(2x+7)+(x+1)(6x-5)=(x+2)-(x-5) x (10x+9)-(5x-1)(2x+3)=8
6x^2+21x-2x-7+6x^2-5x+6x-5=x+2-x+5 10x^2+9x-(10x^2+15x-2x-3)=8
12x^2+20x-12=7 10x^2+9x-10x^2-15x+2x+3=8
12x^2+20x=19 -4x=5
x(12x+20)=19 x=-5/4
x=19 hoac x=-1/12
9 tháng 10 2021
\(a,\Leftrightarrow\left[{}\begin{matrix}x+5=0\\2x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-5\\x=-\dfrac{1}{2}\end{matrix}\right.\\ b,\Leftrightarrow\left(x+2\right)\left(x-3\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=3\end{matrix}\right.\\ c,\Leftrightarrow2x^2-10x-3x-2x^2=26\\ \Leftrightarrow-13x=26\Leftrightarrow x=-2\\ d,\Leftrightarrow x^2-18x+16=0\\ \Leftrightarrow\left(x^2-18x+81\right)-65=0\\ \Leftrightarrow\left(x-9\right)^2-65=0\\ \Leftrightarrow\left(x-9+\sqrt{65}\right)\left(x-9-\sqrt{65}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=9-\sqrt{65}\\9+\sqrt{65}\end{matrix}\right.\)
\(e,\Leftrightarrow x^2-10x-25=0\\ \Leftrightarrow\left(x-5\right)^2-50=0\\ \Leftrightarrow\left(x-5-5\sqrt{2}\right)\left(x-5+5\sqrt{2}\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=5+5\sqrt{2}\\x=5-5\sqrt{2}\end{matrix}\right.\\ f,\Leftrightarrow5x\left(x-1\right)-\left(x-1\right)=0\\ \Leftrightarrow\left(x-1\right)\left(5x-1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{1}{5}\end{matrix}\right.\\ g,\Leftrightarrow2\left(x+5\right)-x\left(x+5\right)=0\\ \Leftrightarrow\left(2-x\right)\left(x+5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=-5\end{matrix}\right.\\ h,\Leftrightarrow x^2+2x+3x+6=0\\ \Leftrightarrow\left(x+3\right)\left(x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-2\end{matrix}\right.\\ i,\Leftrightarrow4x^2-12x+9-4x^2+4=49\\ \Leftrightarrow-12x=36\Leftrightarrow x=-3\)
\(j,\Leftrightarrow x^2\left(x+1\right)+\left(x+1\right)=0\Leftrightarrow\left(x^2+1\right)\left(x+1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x^2=-1\left(vô.lí\right)\\x=-1\end{matrix}\right.\Leftrightarrow x=-1\\ k,\Leftrightarrow x^2\left(x-1\right)=4\left(x-1\right)^2\\ \Leftrightarrow x^2\left(x-1\right)-4\left(x-1\right)^2=0\\ \Leftrightarrow\left(x-1\right)\left(x^2-4x+4\right)=0\\ \Leftrightarrow\left(x-1\right)\left(x-2\right)^2=0\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=2\end{matrix}\right.\)
AH
Akai Haruma
Giáo viên
9 tháng 7 2023
Lời giải:
1.
$M=(x^2+6x+9)+(x^2-9)-2(x^2-2x-8)$
$=x^2+6x+9+x^2-9-2x^2+4x+16=(x^2+x^2-2x^2)+(6x+4x)+(9-9+16)$
$=10x+16=5(2x+1)+11=5.0+11=11$
2.
$V=(9x^2+24x+16)-(x^2-16)-10x=9x^2+24x+16-x^2+16-10x$
$=(9x^2-x^2)+(24x-10x)+(16+16)=8x^2+14x+32$
$=8(\frac{-1}{10})^2+14.\frac{-1}{10}+32=\frac{767}{25}$
3.
$P=(x^2+2x+1)-(4x^2-4x+1)+3(x^2-4)$
$=x^2+2x+1-4x^2+4x-1+3x^2-12$
$=(x^2-4x^2+3x^2)+(2x+4x)+(1-1-12)$
$=6x-12=6.1-12=-6$
4.
$Q=(x^2-9)+(x^2-4x+4)-2x^2+8x$
$=x^2-9+x^2-4x+4-2x^2+8x$
$=(x^2+x^2-2x^2)+(-4x+8x)-9+4$
$=4x-5=4(-1)-5=-9$
\(=\left(2x^3+x^2+10x+5+25\right):\left(2x+1\right)\\ =\left[x^2\left(2x+1\right)+5\left(2x+1\right)+25\right]:\left(2x+1\right)\\ =x^2+5\left(\text{dư }25\right)\)