Tim x: 18/5 * x = 9/7:14/5
a,thuc hien phep tinh: 5*(2^2*3^2)^9*(2^2)^6-2*(2^2*3)^14*3^4/5*2^28*3^18-7*2^29*3^18
b,tim cac so nguyen n sao cho: n^2+5*n+9 la boi cua n+3
c,tim x,y nguyen sao cho: xy+2*x+y+11=0
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
a: \(=\dfrac{17}{19}\cdot\dfrac{19}{17}\cdot\dfrac{4}{5}=\dfrac{4}{5}\)
b: \(=\dfrac{14}{7}\cdot\dfrac{7}{6}=2\cdot\dfrac{7}{6}=\dfrac{14}{6}=\dfrac{7}{3}\)
c: =13/14(4/5+1/5)=13/14
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
\(\dfrac{17}{19}\times\dfrac{12}{15}\times\dfrac{19}{17}=\dfrac{12}{15}\)
\(\left(\dfrac{5}{7}+\dfrac{9}{7}\right)\times\dfrac{21}{18}=2\times\dfrac{7}{6}=\dfrac{7}{3}\)
\(\dfrac{4}{5}\times\dfrac{13}{14}+\dfrac{13}{14}\times\dfrac{1}{5}=\dfrac{13}{14}\)
17/19 x 12/15 x 19/17 (5/7 + 9/7)x 21/18
4/5 x 13/14 + 13/14 x 1/5
\(\dfrac{17}{19}\times\dfrac{12}{15}\times\dfrac{19}{17}.\\ =\dfrac{17}{19}\times\dfrac{19}{17}\times\dfrac{12}{15}.\\ =1\times\dfrac{12}{15}=\dfrac{12}{15}.\\ \left(\dfrac{5}{7}+\dfrac{9}{7}\right)\times\dfrac{21}{18}.\\ =2\times\dfrac{7}{6}=\dfrac{7}{3}.\\ \dfrac{4}{5}\times\dfrac{13}{14}+\dfrac{13}{14}\times\dfrac{1}{5}.\\ =\left(\dfrac{4}{5}+\dfrac{1}{5}\right)\times\dfrac{13}{14}.\\ =1\times\dfrac{13}{14}.\\ =\dfrac{13}{14}.\)
tim x 9/14-x/7:5/3=3/14
\(\frac{9}{14}-\frac{x}{7}:\frac{5}{3}=\frac{3}{14}\Leftrightarrow\frac{9}{14}-\frac{3x}{35}=\frac{3}{14}\Leftrightarrow\frac{3x}{35}=\frac{3}{7}\Leftrightarrow3x=15\Leftrightarrow x=5\)
9/14 - x/7 : 5/3 = 3/14 tim x
9/14-x/7:5/3=6/14
x/7:5/3=3/14
x/7=5/14
x=35/7
tim x;biet
a;x-14=3.x+18
b;|x+3|+|x+9|+|x+5|=4x
\(x-14=3x+18\)
\(\Leftrightarrow\)\(3x-x=-14-18\)
\(\Leftrightarrow\)\(2x=-32\)
\(\Leftrightarrow\)\(x=\frac{-32}{2}\)
\(\Leftrightarrow\)\(x=-16\)
b) Ta có :
\(\left|x+3\right|\ge0\)\(;\)\(\left|x+9\right|\ge0\) và \(\left|x+5\right|\ge0\) nên \(\left|x+3\right|+\left|x+9\right|+\left|x+5\right|\ge0\)
Mà \(\left|x+3\right|+\left|x+9\right|+\left|x+5\right|=4x\) \(\Rightarrow\)\(4x\ge0\)
Vì \(4>0\) nên \(x\ge0\)
\(\Rightarrow\)\(\left|x+3\right|+\left|x+9\right|+\left|x+5\right|=4x\)
\(\Leftrightarrow\)\(x+3+x+9+x+5=4x\)
\(\Leftrightarrow\)\(\left(x+x+x\right)+\left(3+9+5\right)=4x\)
\(\Leftrightarrow\)\(3x+17=4x\)
\(\Leftrightarrow\)\(4x-3x=17\)
\(\Leftrightarrow\)\(x=17\)
Vậy \(x=17\)
\(x-14=3x+18\)
\(x-3x=14+18\)
\(-2x=32\)
\(x=\frac{32}{-2}\)
\(x=-16\)
\(x-14=3x+18\)
\(x-3x=14+18\)
\(-2x=32\)
\(x=32:\left(-2\right)\)
\(x=-16\)
3 tìm x
a)4/9.x=1/9
b)x:-1/12=7/12
c)-5/14:x=-3/10
d)7/18.x-2/3=5/18
e)4/9-7/8.x=-2/3
f)1/6+-5/7:x=-7/18
Mọi người tk mình đi mình đang bị âm nè!!!!!!
Ai tk mình mình tk lại nha !!!
a.1/4
b.-7/144
c.25/21
d.17/7
e.80/63
f.9/7
a)1/4
b)-7/144
c)-25/21
d)17/7
e)16/63
f)9/7
tim x;
5 4/9 + x - 7 7/18 = 15 3/4
\(5\frac{4}{9}+x-7\frac{7}{18}=15\frac{3}{4}\)
\(\frac{49}{9}+x-\frac{133}{18}=\frac{63}{4}\)
\(\frac{49}{9}+x=\frac{833}{36}\)
\(x=\frac{637}{36}\)