Tìm nghiệm của các đa thức
a) \(\left(x-3\right)\times\left(4-5\times x\right)\)
b) \(x^2-2\)
c) \(x^2+\sqrt{3}\)
d) \(x^2+2\times x\)
e) \(x^2+2\times x-3\)
( làm đầy đủ mình tick cho 3 cái nhé)
tìm x,biết
a. \(5\times\left(3+7\times x\right)=400\)
b.\(x\times37+x\times63=1200\)
c.\(x\times6+12:3=40\)
d.\(4+6\times x\left(x+1\right)=70\)
e.\(163:x+34:x=10\)
mik sẽ chỉ tick 2 bn thoy vì mik đag cần gấp
a) \(5\times\left(3+7\times x\right)=400\)
\(3+7\times x=80\)
\(7\times x=77\)
\(x=11\)
b) \(x\times37+x\times63=1200\)
\(x\times\left(37+63\right)=1200\)
\(x\times100=1200\)
\(x=12\)
c) \(x\times6+12:3=40\)
\(x\times6+4=40\)
\(x\times6=36\)
\(x=6\)
d) \(4+6\times\left(x+1\right)=70\)
\(6\times\left(x+1\right)=66\)
\(x+1=11\)
\(x=10\)
e) \(163:x+34:x=10\)
\(\left(163+34\right):x=10\)
\(197:x=10\)
\(x=19,7\)
cho 2 đa thức \(A=2\times x^2\times y^3-3\times x^3\times y^2+x^2\times y^2+1\)
\(B=2\times x^2\times y^3-3\times x^3\times y^2-x^2\times y^2+2\)
Tính \(2\times A-\left(B-\left(A-\left(-4\times B\right)\right)\right)\)
bài 1 : rút gọn các biểu thức sau .
a, \(\sqrt{4\left(a-3\right)^2}+2\sqrt{a^2+4a+4}\left(a< -2\right)\)
b, \(\sqrt{\dfrac{\left(x-2\right)^2}{\left(3-2\right)^2}}+\dfrac{x^2-1}{x-3}\left(x< 3\right)\)
c, \(4x-\sqrt{8}+\dfrac{\sqrt{x^3+2x^2}}{\sqrt{x+2}}\)
bài 2 thực hiện phép tính :\
a, \(\sqrt{8-\sqrt[2]{7}}\times\sqrt{8+\sqrt[2]{7}}\)
b, \(\sqrt{4+\sqrt{8}+}+\sqrt{2}+\sqrt{2+\sqrt{2}}\times\sqrt{2-\sqrt{2+2}}\)
c, \(\left(4+\sqrt{15}\right)\times\sqrt{10}-\sqrt{6}\times\sqrt{4-\sqrt{15}}\)
d, \(\left(2+\sqrt{3}\right)^2-\left(2-\sqrt{3}\right)\times\left(2+\sqrt{3}\right)\)
Bài 1 :
a) \(\sqrt{4\left(a-3\right)^2}+2\sqrt{\left(a^2+4a+4\right)}\)
= \(2\left|a-3\right|+2\left|a+2\right|\)
\(=2.\left(-a+3\right)+2\left(-a-2\right)\)
b) có sai đề ko ?
c) \(4x-\sqrt{8}+\dfrac{\sqrt{x^3+2x^2}}{\sqrt{x+2}}=4x-\sqrt{8}+\sqrt{\dfrac{x^2\left(x+2\right)}{x+2}}=4x-2\sqrt{4}+x=3x-2\sqrt{4}\)
cho: \(f\left(x\right)=a\times x^3+4\times x\times\left(x^2-1\right)+8\)
\(g\left(x\right)=x^3-4\times x\times\left(b\times x+1\right)+c-3\)
tìm a, b, c để \(f\left(x\right)=g\left(x\right)\)
Tìm \(x\in Z\):
a. \(2\times\left(x-5\right)-3\times\left(x-4\right)=\left(-6\right)+15\times\left(-3\right)\)
b.\(\left(2x-5\right)-7=22\)
c.\(\left(2\times\left|x\right|-6\right)\times11=44\)
d.\(\left|x+3\right|+\left|x+5\right|+\left|x+9\right|=4x\)
e.\(\left|x-1\right|+\left|x-5\right|=4\)
g.\(x+\left(x+1\right)+\left(x+2\right)+.......+100=0\)
a) x=53
b) x=17
c) x=5;x=-5
d) x=17
e) x=5
g) ???
Bài 1 Tìm \(x\)
a)\(\left(\dfrac{1}{2}\times x-3\right)\times\left(-\dfrac{1}{3}+x\right)=0\)
b)\(\dfrac{1}{2}\times x^2-\dfrac{1}{5}\times x=0\)
c)\(\dfrac{1`}{4}\times x=\dfrac{1}{16}\times x^2\)
d)\(9\times x^2=1\)
e)\(\left(x-5\right)^2=4\)
a) \(\left(\dfrac{1}{2}x-3\right)\left(-\dfrac{1}{3}+x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x-3=0\\-\dfrac{1}{3}+x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x=0+3\\-\dfrac{1}{3}+x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3:\dfrac{1}{2}\\x=0-\left(-\dfrac{1}{3}\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=\dfrac{1}{3}\end{matrix}\right.\)
d) \(9x^2=1\)
\(\Leftrightarrow x^2=1:9\)
\(\Leftrightarrow x^2=\dfrac{1}{9}\)
\(\Leftrightarrow x^2=\left(\dfrac{1}{3}\right)^2\)
\(\Leftrightarrow x=\dfrac{1}{3}\)
e) \(\left(x-5\right)^2=4\)
\(\Leftrightarrow\left(x-5\right)^2=2^2\)
\(\Leftrightarrow x-5=2\)
\(\Leftrightarrow x=2+5\)
\(\Leftrightarrow x=7\)
Biết \(\left(x^2-2\right)\times P\left(x+1\right)=\left(x^2-3\right)\times P\left(x\right)\).
Chứng minh rằng đa thức P(x) có ít nhất 4 nghiệm.
Tìm x
a, \(\left(2-x\right)\times\left(\dfrac{4}{5}-x\right)< 0\)
b, \(\left(x-\dfrac{3}{2}\right)\times\left(2\times x-1\right)>0\)
c, \(\left(x-\dfrac{4}{7}\right)\div\left(x+\dfrac{1}{2}\right)>0\)
d, \(\left(2\times x-5\right)\div\left(x+1\dfrac{3}{4}\right)< 0\)
Giúp mk với
\(a,\left(2-x\right)\left(\dfrac{4}{5}-x\right)< 0\)
=>Trong 2 số phải có 1 số âm và 1 số dương
Mà \(2-x>\dfrac{4}{5}-x\)
=>\(\dfrac{4}{5}< x< 2\)
Vậy...
Bài 2: Tìm x:
a)\(\dfrac{x-1}{27}\)=\(\dfrac{-3}{1-x}\) c)\(3\times x=2\times y\) và\(x-2\times y=8\)
b)\(\dfrac{4}{5}\)-\(\left|x-\dfrac{1}{2}\right|\)=\(\dfrac{3}{4}\) d)\(\dfrac{x-1}{2005}\)=\(\dfrac{3-y}{2006}\) và x-4009=y
a: \(\Leftrightarrow\left(x-1\right)^2=81\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=9\\x-1=-9\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=10\\x=-8\end{matrix}\right.\)