2/3 :x/5 + 5/7 = 2/7 : 3/5 + 10/9
Ai giúp mk đi !
a,2/3x-3/2x=5/12
b,2/5+3/5×(3x-3×7)=-53/10
c,7/9:(2+3/4x)+5/3=23/27
d,-2/3×x+1/5=3/10
e,|x|-3/4=5/3
Giúp em với ạ
a) \(\dfrac{2}{3}x-\dfrac{3}{2}x=\dfrac{5}{12}\)
\(x\left(\dfrac{2}{3}-\dfrac{3}{2}\right)=\dfrac{5}{12}\)
\(x\cdot\left(-\dfrac{5}{6}\right)=\dfrac{5}{12}\)
\(x=\dfrac{5}{12}:\left(-\dfrac{5}{6}\right)\)
\(x=-\dfrac{1}{2}\)
Vậy \(x=-\dfrac{1}{2}\).
b) \(\dfrac{2}{5}+\dfrac{3}{5}\cdot\left(3x-3\cdot7\right)=-\dfrac{53}{10}\)
\(\dfrac{3}{5}\left(3x-3\cdot7\right)=-\dfrac{53}{10}-\dfrac{2}{5}\)
\(\dfrac{3}{5}\left(3x-3\cdot7\right)=-\dfrac{57}{10}\)
\(3x-3\cdot7=-\dfrac{57}{10}:\dfrac{3}{5}\)
\(3x-3\cdot7=-\dfrac{19}{2}\)
\(3x-21=-\dfrac{19}{2}\)
\(3x=-\dfrac{19}{2}+21\)
\(3x=\dfrac{23}{2}\)
\(x=\)\(\dfrac{23}{2}:3\)
\(x=\dfrac{23}{6}\)
Vậy \(x=\dfrac{23}{6}\).
c) \(\dfrac{7}{9}:\left(2+\dfrac{3}{4x}\right)+\dfrac{5}{3}=\dfrac{23}{27}\)
\(\dfrac{7}{9}:\left(2+\dfrac{3}{4x}\right)=\dfrac{23}{27}-\dfrac{5}{3}\)
\(\dfrac{7}{9}:\left(2+\dfrac{3}{4x}\right)=-\dfrac{22}{27}\)
\(2+\dfrac{3}{4x}=\dfrac{7}{9}:-\dfrac{22}{27}\)
\(2+\dfrac{3}{4x}=-\dfrac{21}{22}\)
\(\dfrac{3}{4x}=-\dfrac{21}{22}-2\)
\(\dfrac{3}{4x}=-\dfrac{65}{22}\)
\(4x=\dfrac{3\cdot22}{-65}\)
\(4x=-\dfrac{66}{65}\)
\(x=-\dfrac{66}{65}:4\)
\(x=-\dfrac{33}{130}\)
Vậy \(x=-\dfrac{33}{130}\).
d) \(-\dfrac{2}{3}x+\dfrac{1}{5}=\dfrac{3}{10}\)
\(-\dfrac{2}{3}x=\dfrac{3}{10}-\dfrac{1}{5}\)
\(-\dfrac{2}{3}x=\dfrac{1}{10}\)
\(x=\dfrac{1}{10}:-\dfrac{2}{3}\)
\(x=-\dfrac{3}{20}\)
Vậy \(x=-\dfrac{3}{20}\).
e) \(\left|x\right|-\dfrac{3}{4}=\dfrac{5}{3}\)
\(\left|x\right|=\dfrac{5}{3}+\dfrac{3}{4}\)
\(\left|x\right|=\dfrac{29}{12}\)
\(x=\dfrac{29}{12}\) hoặc \(=-\dfrac{29}{12}\)
Vậy \(x\in\left\{\dfrac{29}{12};-\dfrac{29}{12}\right\}\).
Quy đồng mẫu số các phân số sau
a.7/9 và 2/5 b.6/7 và 17/21 c.2/3:1/4 và 5/9
ai nhanh mik tick cho
`a,MSC:45`
`7/9=(7xx5)/(9xx5)=35/45`
`2/5=(2xx9)/(5xx9)=18/35`
`b,MSC:21`
`6/7=(6xx3)/(7xx3)=18/21`
`17/21` giữ nguyên
`c,MSC:36`
`2/3=(2xx12)/(3xx12)=24/36`
`1/4=(1xx9)/(4xx9)=9/36`
`5/9=(5xx4)/(9xx4)=20/36`
\(a,\dfrac{7}{9}=\dfrac{7.5}{9.5}=\dfrac{35}{45}\\\dfrac{2}{5}=\dfrac{2.9}{5.9}=\dfrac{18}{45}\\ b,\dfrac{6}{7}=\dfrac{6.3}{7.3}=\dfrac{18}{21}\\ \dfrac{17}{21}giữnguyên\\ c,\dfrac{2}{3}=\dfrac{2.12}{3.12}=\dfrac{24}{36}\\ \dfrac{1}{4}=\dfrac{1.9}{4.9}=\dfrac{9}{36}\\ \dfrac{5}{9}=\dfrac{5.4}{9.4}=\dfrac{20}{36}\)
Tìm x
(2x-1)2+(x+3)2-5.(x+7).(x-70=0
giúp mk ik,mk cần gấp lắm, các bn giúp mk mk sẽ giúp lại các bn
\(\left(2x-1\right)^2+\left(x+3\right)^2-5\left(x+7\right)\left(x-7\right)=0\\ 4x^2-4x+1+x^2+6x+9-5x^2+245=0\\ 2x+255=0\\ 2x=-255\\ x=-\dfrac{255}{2}\)
tìmx,y,z:
a,x-1/6=7×y+3/5=z/3 và2x+7y+2z=45
b,5-x/3=2-y/2=z+3 và2x+3y-4z=7
Ai họcgiỏi toan giúp mk vs
hok giỏi cái ***
kéo xuống hết nha!!!!
chịch ko em!!!!ớ ớ
giúp mk vs dc không
4/7+1/3/x=2/5
<=> 4/7 + 1/3x = 2/5 <=> 1/3x = -6/35 <=> x = -35/18
a) |x - 1/2 |= 1/3
b) 14/15 : 9/10= x : 3/7
c) 6/5 : 8 = 2/5 : x
d) 3x - 7 / 8 = 5/2
e) x/2 = 8/x
g) 5/9 :x = 7/4 : 3/10
giúp mk vs mk tick cho
\(/x-\frac{1}{2}/=\frac{1}{3}\\ =>\orbr{\begin{cases}x-\frac{1}{2}=\frac{1}{3}\\x-\frac{1}{2}=-\frac{1}{3}\end{cases}}\\ =>\orbr{\begin{cases}x=\frac{1}{3}+\frac{1}{2}\\x=-\frac{1}{3}+\frac{1}{2}\end{cases}}\\ =>\orbr{\begin{cases}x=\frac{5}{6}\\x=\frac{1}{6}\end{cases}}\)
\(a,|x-\frac{1}{2}|=\frac{1}{3}\)
\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{2}=\frac{1}{3}\\x-\frac{1}{2}=-\frac{1}{3}\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{5}{6}\\x=\frac{1}{6}\end{cases}}}\)
\(b,\frac{14}{15}:\frac{9}{10}=x:\frac{3}{7}\)
\(\frac{28}{27}=x:\frac{3}{7}\)
\(x=\frac{4}{9}\)
\(c,\frac{6}{5}:8=\frac{2}{5}:x\)
\(\frac{3}{20}=\frac{2}{5}:x\)
\(x=\frac{8}{3}\)
\(d,3x-\frac{7}{8}=\frac{5}{2}\)
\(3x=\frac{27}{8}\)
\(x=\frac{9}{8}\)
tính nhanh:
1+2+3+4+5+6+7+8+9
AI NHANH TAY MÌNH TICK CHO Ạ
tìm x:
a) -7(5-x)-2(x-10)=15
b) 4(x-5)-3(x+7)= -19
c) 4(2-x)+3(x-5)=14
d) -7(3x-5)+2(7x-14)=28
e) 5(4-x)-7(2-x)=-2
f) 5(x-7)+10(3-x)=20
g) 7(5-x)+5(x-2)=15
h) 5(x-6)-2(x+3)=12
i) 3(x-4)-(8-x)=12
giúp mk vs
Tìm x
(2x-1)2+(x+3)2-5.(x+7).(x-7)=0
Qúy nhất mấy pan giúp mk làm câu này