\(2\cdot3^{x+1}=54\)

\(3^{x+1}=\frac{54}{2}\)

\(3^{x+1}=27\)

\(3^{x+1}=3^3\)

\(=>x+1=3\)

        \(x=3-1=2\)

-15(x+2) + 7(2x3) = -50

-15(x+2) + 7 x 6   = -50

-15(x+2) + 42       = -50

-15(x+2)               = -50 - 42

-15(x+2)               = -92

(x+2)                    = -92 : -15

(x+2)                    = 6,1333

x                          = 6,1333 + 2

x                          = 8,1333

-15(x+2)+7(2.3)=-50

-15(x+2)+7.6=-50 

-15(x+2)+42=-50

-15(x+2)=-50-42

-15(x+2)=-92

x+2=-92:-15

x+2=92/15

x=92/15-2

x=62/15

moi nguoi nho tk va ket ban voi minh nhe

KQ là: 5800

5800 là đúng đó ! 

k mình nhé

\(1,3x-7=19\\ \Rightarrow3x=26\\ \Rightarrow x=\dfrac{26}{3}\\ 2,\left(2x+1\right)\left(x-3\right)=0\\ \Rightarrow\left[{}\begin{matrix}2x+1=0\\x-3=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=3\end{matrix}\right.\\ 3,3x+\dfrac{2}{4}+1=5x-\dfrac{1}{3}\\ \Rightarrow5x-\dfrac{1}{3}-3x-\dfrac{2}{4}-1=0\\ \Rightarrow2x-\dfrac{11}{6}=0\\ \Rightarrow2x=\dfrac{11}{6}\\ \Rightarrow x=\dfrac{11}{12}\)

\(4,\dfrac{x}{15}+\dfrac{1}{2}-\dfrac{x}{50}=\dfrac{5}{6}\\ \Rightarrow\dfrac{x}{15}-\dfrac{x}{50}=\dfrac{5}{6}-\dfrac{1}{2}\\ \Rightarrow x\left(\dfrac{1}{15}-\dfrac{1}{50}\right)=\dfrac{1}{3}\\ \Rightarrow\dfrac{7}{150}x=\dfrac{1}{3}\\ \Rightarrow x=\dfrac{50}{7}\)

Bạn cho mình đề bài

đúng rồi

Số?

\(\frac{1}{1}\cdot2=2\)

\(\frac{1}{2}\cdot3=\frac{3}{2}\)

sao mai van trua co ngoui cha loi

50%=1/2

Có y+1/2=1/2x3

y=1/2x2=1

\(\dfrac{54\times50+49\times100}{37\times38+126\times19}\)

\(=\dfrac{50\times\left(49\times2+54\right)}{38\times\left(63+37\right)}\)

\(=\dfrac{50\times152}{38\times100}\)

\(=\dfrac{25\times2\times4\times38}{38\times25\times4}\)

\(=2\)