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\(2^x.2^{x+3}=64^2:2^5\)
\(2^x.2^x.2^3=2^{12}:2^5\)
\(2^x.\left(1+8\right)=2^7\)
\(2^x.9=2^7\)
\(\Rightarrow x=\varnothing\)
\(2^{2x+3}=64^2:2^5\)
\(\Leftrightarrow2^{2x+3}=2^7\)
hay x=2
1: =>x+1/2=0 hoặc 2/3-2x=0
=>x=-1/2 hoặc x=1/3
2: =>7/6x=5/2:3,75=2/3
=>x=2/3:7/6=2/3*6/7=12/21=4/7
3: =>2x-3=0 hoặc 6-2x=0
=>x=3 hoặc x=3/2
4: =>-5x-1-1/2x+1/3=3/2x-5/6
=>-11/2x-3/2x=-5/6-1/3+1
=>-7x=-1/6
=>x=1/42
P(x) + Q(x)= ( x^5 - 2x^2 + 7x^4 - 9x^3 - 1/4x) + ( 5x^4 - x^5 + 4x^2 - 2x^3 - 1/4)
= x^5 - 2x^2 + 7x^4 - 9x^3 - 1/4x + 5x^4 - x^5 + 4x^2 - 2x^3 - 1/4
= ( x^5 - x^5 ) - ( 2x^2 + 4x^2) + ( 7x^4 + 5x^4) - ( 9x^3 - 2x^3) - 1/4x - 1/4
= 6x^2 + 12x^4 - 6x^3 - 1/4x - 1/4
P(x) - Q(x)= ( x^5 - 2x^2 + 7x^4 - 9x^3 -1/4x) - ( 5x^4 - x^5 + 4x^2 - 2x^3 -1/4)
= x^5 - 2x^2 + 7x^4 - 9x^3 - 1/4x - 5x^4 + x^5 - 4x^2 + 2x^3 + 1/4
= ( x^5 + x^5) - ( 2x^2 - 4x^2) + ( 7x^4 - 5x^4) - ( 9x^3 + 2x^3) - 1/4x + 1/4
= 2x^5 - (-2)x^2 + 2x^4 - 11x^3 - 1/4x + 1/4
P(x)=x^5+ 7x^4- 9x^3+ 2x^2-1/4x-0
Q(x)=(-x^5+5x^4- 2x^3+ 4x^2+0x-1/4
= 12x^4-11x^3+ 6x^2-1/4x-1/4
a. \(2\left(\dfrac{1}{2}x-\dfrac{1}{3}\right)-\dfrac{3}{2}=\dfrac{1}{4}\\ \Leftrightarrow2\left(\dfrac{1}{2}x-\dfrac{1}{3}\right)=\dfrac{7}{4}\\ \Leftrightarrow\dfrac{1}{2}x-\dfrac{1}{3}=\dfrac{7}{8}\\ \Leftrightarrow\dfrac{1}{2}x=\dfrac{29}{24}\\ \Leftrightarrow x=\dfrac{29}{12}\)
b. \(\dfrac{3}{4}-2\left(2x-\dfrac{2}{3}\right)=2\\ \Leftrightarrow2\left(2x-\dfrac{2}{3}\right)=-\dfrac{5}{4}\\ \Leftrightarrow2x-\dfrac{2}{3}=-\dfrac{5}{8}\\ \Leftrightarrow2x=\dfrac{1}{24}\\ \Leftrightarrow x=\dfrac{1}{48}\)
c. \(\left(2x-3\right)\left(6-2x\right)=0\\ \Rightarrow\left[{}\begin{matrix}2x-3=0\\6-2x=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=3\end{matrix}\right.\)
Vậy ..........
\(2+4+6+...+2x+\left(2x+2\right)=10050\)
\(\Rightarrow2\left(1+2+3+...+x+x+1\right)=10050\)
\(\Rightarrow1+2+3+...+x+x+1=10050:2\)
\(\Rightarrow1+2+3+...+s+x+1=5025\)
\(\Rightarrow\dfrac{x.\left(x+1\right)}{2}=5025\)
\(\Rightarrow x.\left(x+1\right)=5025.2\)
\(\Rightarrow x.\left(x+1\right)=10050\)
Mà 10050 không bằng tích của 2 số tự nhiên liên tiếp
\(\Rightarrow\) không tồn tại số tự nhiên x thỏa mãn
Mình ko chắc lắm đâu nhé :)
P(x) = x^5 - 2x^2 + 7x^4 - 9x^3 - 1/4x
=x5+7x4-9x3-2x2-1/4x
Q(x) = 5x^4 - x^5 + 4x^2 - 2x^3 - 1/4
=-x5+5x4-2x3+4x2-1/4
P(x)+Q(x)=x5+7x4-9x3-2x2-1/4x -x5+5x4-2x3+4x2-1/4
=x5-x5+7x4+5x4-9x3-2x3-2x2+4x2-1/4x-1/4
=12x4-11x3+2x2-1/4x-1/4
P(x)-Q(x)=x5+7x4-9x3-2x2-1/4x +x5-5x4+2x3-4x2+1/4
=x5+x5+7x4-5x4-9x3+2x3-2x2-4x2-1/4x-1/4
=2x5+2x4-7x3-6x2-1/4x-1/4