-3x - 5 = -7 -13
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
BK
1
TA
1 tháng 11 2019
\(\left(\sqrt{7+3x}-4\right)+\left(\sqrt{13-3x}-2\right)+5.\left(\sqrt{\left(7+3x\right)\left(13-3x\right)}-8\right)=0\)
=) \(\frac{7+3x-16}{\sqrt{7+3x}+4}+\frac{13-3x-4}{\sqrt{13-3x}+2}+5.\left(\sqrt{91+18x-9x^2}-8\right)=0\)
=) \(\frac{3\left(x-3\right)}{\sqrt{7+3x}+4}+\frac{3\left(3-x\right)}{\sqrt{13-3x}+2}+\frac{5\left(27+18x-9x^2\right)}{\sqrt{91+18x-9x^2}+8}=0\)
=) \(\frac{3\left(x-3\right)}{\sqrt{7+3x}+4}-\frac{3\left(x-3\right)}{\sqrt{13-3x}+2}-\frac{45\left(x+1\right)\left(x-3\right)}{\sqrt{91+18x-9x^2}+8}=0\)
=) đến đây chắc là tự làm đc rồi
HC
1
16 tháng 11 2022
Đặt \(\sqrt{7+3x}=a;\sqrt{13-3x}=b\)
=>a+b+5ab=46
=>(a+b)^2=46-5ab
=>a^2+b^2+2ab=2116-460ab+25a^2b^2
=>25a^2b^2-460ab+2116=7+3x+13-3x+2ab
=>25a^2b^2-462ab+2096=0
=>\(\left[{}\begin{matrix}ab=\dfrac{262}{25}\\ab=8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left(7+3x\right)\cdot\left(13-3x\right)=109.8304\\\left(7+3x\right)\left(13-3x\right)=64\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}91-21x+39x-9x^2=109.8304\\91-21x+39x-9x^2=64\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}-9x^2+18x-18.8304=0\\-9x^2+18x+27=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)
HC
0
PT
2
11 tháng 5 2021
a)5-(13-3x)=109-(32+109)
5-(13-3x)=-32
13-3x =37
3x =-24
3x =-6
11 tháng 5 2021
a)5-(13-3x)=109-(32+109)
5-13+3x =109-32-109
-8+3x=-32
3x=-32-(-8)
3x=-24
x=-24:3
x=-8
b)|3x-6|+(x-22)=0
(3x-6)+(x-22)=0
3x-6+x-22=0
3x+x=0+6+22
4x=10
x=\(\dfrac{5}{2}\)
c)/7-2x/=-13-5.(-8)
|7-2x|=27
⇒7-2x=27 hoặc 7-2x=-27
x=-10 hoặc x=-17
15 tháng 3 2017
\(a,\frac{7}{3}x+5=\frac{9}{6}x-7\)
\(\frac{7}{3}x-\frac{9}{6}x=-7-5\)
\(\left(\frac{7}{3}-\frac{9}{6}\right).x=-12\)
\(\frac{5}{6}.x=-12\)
\(x=\left(-12\right):\frac{5}{6}\)
\(x=-\frac{72}{5}\)
\(b,3x+\frac{6}{4}=5-\frac{7x}{6}\)
\(3x+\frac{7x}{6}=5-\frac{6}{4}\)
\(\left(3+\frac{7}{6}\right).x=\frac{7}{2}\)
\(\frac{25}{6}.x=\frac{7}{2}\)
\(x=\frac{7}{2}:\frac{25}{6}\)
\(x=\frac{21}{25}\)
\(c,\frac{12}{5}x+6=\frac{17}{3}x+12\)
\(\frac{12}{5}x-\frac{17}{3}x=12-6\)
\(-\frac{49}{15}x=6\)
\(x=6:\left(-\frac{49}{15}\right)\)
\(x=-\frac{90}{49}\)
\(d,6\left(3x+7\right)=12\left(2x-4\right)\)
\(18x+42=24x-48\)
\(18x-24x=-48-42\)
\(-6x=-90\)
\(x=15\)
\(e,13\left(2x-9\right)=8\left(3x-13\right)\)
\(26x-117=24x-104\)
\(26x-24x=-104+117\)
\(2x=13\)
\(x=\frac{13}{2}\)
16 tháng 3 2020
\(\frac{x}{2}-\left(\frac{3x}{5}-\frac{13}{5}\right)=-\left(\frac{7}{5}+\frac{7}{10x}\right)\)
\(\frac{x}{2}-\frac{3x}{5}+\frac{13}{5}=-\frac{7}{5}-\frac{7}{10x}\)
\(\frac{x}{2}-\frac{x}{15}+\frac{7}{10x}=-\frac{7}{5}-\frac{13}{5}\)
\(\frac{15x}{30}-\frac{2x}{30}+\frac{7}{10x}=-4\)
\(\frac{13x}{30}+\frac{7}{10x}=-4\)
\(13x^2+21=-120x\)
\(13x^2+21+120x=0\)
\(\orbr{\begin{cases}-\frac{60-\sqrt{3327}}{13}\\-\frac{60+\sqrt{3327}}{13}\end{cases}}\)
H
16 tháng 9 2023
\(\dfrac{x}{2}-\left(\dfrac{3x}{5}-\dfrac{13}{5}\right)=\dfrac{7}{5}+\dfrac{7}{10}x\\ \Rightarrow\dfrac{x}{2}-\dfrac{3x}{5}+\dfrac{13}{5}=\dfrac{7}{5}+\dfrac{7x}{10}\\ \Rightarrow\dfrac{5x}{10}-\dfrac{6x}{10}+\dfrac{26}{10}=\dfrac{14}{10}+\dfrac{7x}{10}\\ \Rightarrow\dfrac{5x}{10}-\dfrac{6x}{10}-\dfrac{7x}{10}=\dfrac{14}{10}-\dfrac{26}{10}\\ \Rightarrow\dfrac{-8x}{10}=-\dfrac{12}{10}\\ \Rightarrow\dfrac{-4x}{5}=-\dfrac{6}{5}\\ \Rightarrow-20x=-30\\ \Rightarrow x=\dfrac{3}{2}\)
18 tháng 4 2023
\(1,-\dfrac{4}{7}+\dfrac{2}{3}\times\dfrac{-9}{14}\)
\(=\dfrac{-4}{7}+\dfrac{-18}{42}\)
\(=\dfrac{-4\times6}{7\times6}+\dfrac{-18}{42}\)
\(=\dfrac{-20}{42}+\dfrac{-18}{42}\)
\(=-\dfrac{38}{42}\)
\(=-\dfrac{19}{21}\)
\(2,\dfrac{17}{13}-\left(\dfrac{4}{13}-11\right)\)
\(=\dfrac{17}{13}-\dfrac{4}{13}+11\)
\(=\dfrac{13}{13}+11\)
\(=1+11\)
\(=12\)
\(3,8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)\)
\(=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)\)
\(=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}\)
\(=\dfrac{58}{7}-\dfrac{30}{7}-\dfrac{31}{9}\)
\(=\dfrac{28}{7}-\dfrac{31}{9}\)
\(=\dfrac{28\times9}{7\times9}-\dfrac{31\times7}{9\times7}\)
\(=\dfrac{252}{63}-\dfrac{217}{63}\)
\(=\dfrac{35}{63}\)
\(=\dfrac{5}{9}\)
\(5,\left(\dfrac{2}{3}-1\dfrac{1}{2}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{2}{3}-\dfrac{3}{2}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{2\times2}{3\times2}-\dfrac{3\times3}{2\times3}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{4}{6}-\dfrac{9}{6}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\dfrac{-5}{6}:\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\dfrac{-5}{6}\times\dfrac{3}{4}+\dfrac{1}{2}\)
\(=\dfrac{-15}{24}+\dfrac{1}{2}\)
\(=\dfrac{-15}{24}+\dfrac{1\times12}{2\times12}\)
\(=\dfrac{-15}{24}+\dfrac{12}{24}\)
\(=\dfrac{-3}{24}\)
\(=-\dfrac{1}{8}\)
\(6,\dfrac{-5}{13}+\dfrac{2}{5}+\dfrac{-8}{13}+\dfrac{3}{5}-\dfrac{3}{7}\)
\(=\left(\dfrac{-5}{13}+\dfrac{-8}{13}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{3}{7}\)
\(=\dfrac{-13}{13}+\dfrac{5}{5}-\dfrac{3}{7}\)
\(=-1+1-\dfrac{3}{7}\)
\(=-\dfrac{3}{7}\)
\(7,\dfrac{6}{5}\times\dfrac{3}{7}+\dfrac{6}{5}:\dfrac{7}{10}+\dfrac{6}{5}\)
\(=\dfrac{6}{5}\times\dfrac{3}{7}+\dfrac{6}{5}\times\dfrac{10}{7}+\dfrac{6}{5}\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+1\right)\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+\dfrac{1\times7}{1\times7}\right)\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+\dfrac{7}{7}\right)\)
\(=\dfrac{6}{5}\times\dfrac{20}{7}\)
\(=\dfrac{120}{35}\)
\(=\dfrac{24}{7}\)
-3x-5=-7-13
-3x-5=(-20)
-3x=(-20)+5
-3x=(-15)
x=(-15):(-3)
x=5