5.(3x+8)-7.(2x+3)=16

=> 15x+40-14x-21=16

=>(15x-14x)+(40-21)

=> x+19=16

=>x=-3. Vậy x=-3

k cho mik nha

Chúc bạn hok tốt

\(5\left(3x+8\right)-7\left(2x+3\right)=16\)

\(15x+40-14x-21=16\)

\(x+19=16\)

\(x+19-16=0\)

\(x+3=0\)

\(x=-3\)

a) \(3\left(2x-5\right)+125=134\)

\(\Leftrightarrow3\left(2x-5\right)=9\)

\(\Leftrightarrow2x-5=3\)

\(\Leftrightarrow2x=8\Leftrightarrow x=4\)

b) \(\left(2x+5\right)+\left(2x+3\right)+\left(2x+1\right)=27\)

\(\Leftrightarrow6x+9=27\)

\(\Leftrightarrow6x=18\Leftrightarrow x=3\)

d) \(27\left(x-27\right)-27=0\)

\(\Leftrightarrow27\left(x-27\right)=27\)

\(\Leftrightarrow x-27=1\Leftrightarrow x=28\)

c đâu

Bằng 0 chứ nhỉ em ?

(x-5) . (2x-4)= 0

\(\left[{}\begin{matrix}x-5=0\\2x-4=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=5\\2x=4\end{matrix}\right.< =>\left[{}\begin{matrix}x=5\\x=2\end{matrix}\right.\)

(x-5) . (2x-4)= 5

<=> 2x^2 - 4x - 10x + 20 = 5

<=> 2x^2 - 14x + 15 = 0

Giải pt bâc hai ra đc : \(x=\dfrac{7+\sqrt{19}}{2}\)và \(x2=\dfrac{7-\sqrt{19}}{2}\)

a/\(\dfrac{7}{2}-2x=5\dfrac{1}{3}:\dfrac{8}{3}\)
\(\dfrac{7}{2}-2x=\dfrac{16}{3}:\dfrac{8}{3}\)
\(\dfrac{7}{2}-2x=2\)
\(2x=\dfrac{7}{2}-2\)
\(2x=\dfrac{3}{2}\)
\(x=\dfrac{3}{2}:2\)
\(x=\dfrac{3}{4}\)
b/Đề là gì ạ?

a, \(\dfrac{5}{9}.\dfrac{10}{11}+\dfrac{5}{9}.\dfrac{14}{11}-\dfrac{5}{9}.\dfrac{15}{11}=\dfrac{5}{9}.\left(\dfrac{10}{11}+\dfrac{14}{11}-\dfrac{15}{11}\right)=\dfrac{5}{9}.\dfrac{9}{11}=\dfrac{5}{11}\)

b, \(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{3}{13}.\dfrac{6}{7}\)\(=\dfrac{6}{7}.\left(\dfrac{8}{13}-\dfrac{3}{13}\right)+\dfrac{6}{13}.\dfrac{9}{7}=\dfrac{6}{7}.\dfrac{5}{13}+\dfrac{54}{91}=\dfrac{30}{91}+\dfrac{54}{91}=\dfrac{84}{91}=\dfrac{12}{13}\)

Bạn ơi, gõ latex cho dễ nhìn nhé!

\(\left(x+2\right)-2=0\)

\(\Rightarrow x+2-2=0\)

\(\Rightarrow x=0\)

\(\left(x+3\right)+1=7\)

\(\Rightarrow x+3+1=7\)

\(\Rightarrow x+4=7\)

\(\Rightarrow x=3\)

\(\left(3x-4\right)+4=12\)
\(\Rightarrow3x-4+4=12\)

\(\Rightarrow3x=12\)

\(\Rightarrow x=4\)

\(\left(5x+4\right)-1=13\)

\(\Rightarrow5x+4-1=13\)

\(\Rightarrow5x+3=13\)

\(\Rightarrow5x=10\)

\(\Rightarrow x=2\)

\(\left(4x-8\right)-3=5\)

\(\Rightarrow4x-8-3=5\)

\(\Rightarrow4x-11=5\)

\(\Rightarrow4x=16\)

\(\Rightarrow x=4\)

\(8-\left(2x+4\right)=2\)

\(\Rightarrow8-2x-4=2\)

\(\Rightarrow4-2x=2\)

\(\Rightarrow2x=2\)

\(\Rightarrow x=1\)

\(7+\left(5x+2\right)=14\)

\(\Rightarrow7+5x+2=14\)

\(\Rightarrow9+5x=14\)

\(\Rightarrow5x=5\)

\(\Rightarrow x=1\)

\(5-\left(3x-11\right)=1\)

\(\Rightarrow5-3x+11=1\)

\(\Rightarrow16-3x=1\)

\(\Rightarrow3x=15\)

\(\Rightarrow x=5\)

24 chia hết cho 2x-1

=> 2x-1 \(\in\) Ư(24)

=> 2x-1 \(\in\) {1,2,3,4,6,8,12,24,-1,-2,-3,-4,-6,-8,-12,-24}

=> 2x \(\in\) { 2; 3;4;5;7;9;13;25;0;-1;-2;-3;-5;-7;-11;-23}

=> x \(\in\) {1;\(\dfrac{3}{2}\); 2; \(\dfrac{5}{2}\); \(\dfrac{7}{2}\);\(\dfrac{9}{2}\); \(\dfrac{13}{2}\); \(\dfrac{25}{2}\); 0;\(\dfrac{-1}{2}\); -1; \(\dfrac{-3}{2}\); \(\dfrac{-5}{2}\); \(\dfrac{-7}{2}\); \(\dfrac{-11}{2}\); \(\dfrac{-23}{2}\)}

Vậy...