thu gon bieu thuc
2x(1-x)+2x^2
thu gon bieu thuc sau (2x-1)^3-(3x^2-1)(x-2)-(x+3)^3
Ta có: \(\left(2x-1\right)^3-\left(3x^2-1\right)\left(x-2\right)+\left(x+3\right)^3\)
\(=8x^3-12x^2+6x-1-\left(3x^3-6x^2-x+2\right)+x^3+9x^2+27x+27\)
\(=9x^3-3x^2+33x+26-3x^3+6x^2+x-2\)
\(=6x^3+3x^2+34x+24\)
thu gon bieu thuc |2x+3|-x=1
giúp mk gấp nha
thanks
\(\left|2x+3\right|-x=1\)
\(\Leftrightarrow\orbr{\begin{cases}2x+3=x+1\\2x+3=-x-1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x-x=1-3\\2x+x=-1-3\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=-2\\3x=-4\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=-2\\x=-\frac{4}{3}\end{cases}}\)
rut gon bieu thuc: 2x2(x-2) - 2x(x-1)(x+1)
\(2x^2\left(x-2\right)-2x\left(x-1\right)\left(x+1\right)=2x^3-4x^2-2x^3+2x=-4x^2+2x=-2x\left(2x-1\right)\)
\(2x^2\left(x-2\right)-2x\left(x-1\right)\left(x+1\right)\)
\(=2x^3-4x^2-2x\left(x^2-1\right)\)
\(=2x^3-4x^2-2x^3+2x=-4x^2+2x\)
rut gon bieu thuc
(2x-1).(x-2)
thu gon bieu thuc
(x+1)^3-x(x^2+3)
x+2x+4x+...+125x+126x bang cach thu gon cac bieu thuc sau:
Đề không đúng
Tự dưng 1x+2x+4x+......+125x + 126x là sao
thu gon bieu thuc sau:
x+2x+3x+4x+...+125x+126
cho A= (2x-1)^2 -5x.(x-1)+2.(x+1).(x-2) rut gon bieu thuc A
\(A=\left(2x-1\right)^2-5x\left(x-1\right)+2\left(x+1\right)\left(x-2\right)\)
\(=4x^2-4x+1-5x^2+5x+2\left(x^2-x-2\right)\)
\(=x^2-x-3\)
rut gon bieu thuc 2ax^2-a(1+2x^2)-[a-x(x+a)]
2ax^2-a(1+2x^2)-[a-x(x+a)]
=2ax2-2ax2+a+x2-ax+a
=(2ax2-2ax2)-(a+a)+ax+x2
=0-2a+ax+x2
=x2+ax-2a