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90/31

x:8/11=11/3

x=11/3X8/11

x=8/3

b) 2/5:x=1/4

x=2/5:1/4

x=8/5

c)4/5+5/7:x=1/6=?

ai tích mình tích lại 

a) x = 88/33=8/3

b) x = 8/5

c) x = 150/133

a) x / 8/11 = 11/3

             x = 11/3 * 8/11

             x = 88/33

b) 2/5 / x = 1/4

           x = 2/5 / 1/4

           x = 8/5

c) 4/5 + 5/7 / x = 1/6

        53/35 / x = 1/6

                   x = 53/35 / 1/6 

                   x = 318/35

Ai k mk mk k lại

vì x<1 nên 2x<2. Do đó, 2x-8<0 suy ra |2x-8|=8-2x.

đề ra trở thành        B=8-2x-x+1=9-3x

Ta có: \(\frac{x+1}{99}+\frac{x+2}{98}=\frac{x+3}{97}+\frac{x+4}{96}\)

\(\Rightarrow\left(\frac{x+1}{99}+1\right)+\left(\frac{x+2}{98}+1\right)=\left(\frac{x+3}{97}+1\right)+\left(\frac{x+4}{96}+1\right)\)

\(\Rightarrow\frac{x+100}{99}+\frac{x+100}{98}-\frac{x+100}{97}-\frac{x+100}{96}=0\)

\(\Rightarrow\left(x+100\right)\left(\frac{1}{99}+\frac{1}{98}-\frac{1}{97}-\frac{1}{96}\right)=0\)

\(\Rightarrow x+100=0\Rightarrow x=-100\)

Kb vs cho tớ nha mn!

bạn ơi bạn có giải được 2 bài này ko

tìm x biết [x mũ 3+5].[x mũ 3 +10].[x mũ 3 +15].[x mũ 3 +30]<0

[x -5] tất cả mũ 4=[x -5] tất cả mũ 6                                                                                                                                                               bn giải được mk tk luôn cho thanks bạn         

49. D

50. C

49.D

50.C

49. D

50. C

a) \(\Rightarrow\left(2x-3\right)^2=49\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=7\\2x-3=-7\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

b) \(\Rightarrow\left(x-5\right)\left(2x+7\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-\dfrac{7}{2}\end{matrix}\right.\)

c) \(\Rightarrow x\left(x-5\right)+2\left(x-5\right)=0\Rightarrow\left(x-5\right)\left(x+2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

a, ⇒ (2x - 3)² = 49

    ⇒  (2x - 3)² = \(\left(\pm7\right)^2\)

    ⇒ \(\left[{}\begin{matrix}2x-3=7\\2x-3=-7\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=10\\2x=-4\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

b, ⇒ 2x.(x - 5) + 7.(x - 5) = 0

    ⇒ (x - 5).(2x + 7)  = 0

    ⇒ \(\left[{}\begin{matrix}x-5=0\\2x+7=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\2x=-7\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-\dfrac{7}{2}\end{matrix}\right.\)

c, ⇒ x² - 5x + 2x - 10 = 0

    ⇒ (x² - 5x) + (2x - 10) = 0

    ⇒ x.(x - 5) +2.(x - 5)    = 0

    ⇒ (x - 5).(x + 2)=0

    \(\Rightarrow\left[{}\begin{matrix}x+2=0\\x-5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-2\\x=5\end{matrix}\right.\)

\(a.7,5\times x+x\times3,5=39,93\)

\(\Rightarrow x\times\left(7,5+3,5\right)=39,93\)

\(\Rightarrow x\times11=39,93\)

\(\Rightarrow x=39,93:11\)

\(\Rightarrow x=3,63\)

\(b.x:4+x=3,75\)

\(\Rightarrow x:\frac{4}{1}+x=3,75\)

\(\Rightarrow x\times\frac{1}{4}+x=3,75\)

\(\Rightarrow x\times\left(\frac{1}{4}+1\right)=3,75\)

\(\Rightarrow x\times1,25=3,75\)

\(\Rightarrow x=3,75:1,25\)

\(\Rightarrow x=3\)

a) 7,5 *x + x*3,5=39,93

(7,5 + 3,5) * x=39,93

11 * x = 39,93

x= 39,93 : 11

x= 3,63

b)x : 4 + x=3,75

x * 1/4 + x *1 =3,75

x * (1/4 + 1) = 3,75

x * 5/4 = 3,75

x = 3,75 : 5/4

x= 3