|2x+3|+2|4-x|=5
giúp mik với
a) âm 3 phần 2 - 2x + 3 phần 4 = - 2
b) ( âm 2 phần 3 x - 3 phần 5 )(3 phần âm 2 - 10 phần 3 ) = 2 phần 5
Giúp mik vs
a, Ta có : \(-\dfrac{3}{2}-2x+\dfrac{3}{4}=-2\)
\(\Rightarrow-2x=-2+\dfrac{3}{2}-\dfrac{3}{4}=-\dfrac{5}{4}\)
\(\Rightarrow x=\dfrac{5}{8}\)
Vậy ...
b, Ta có : \(\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)\left(-\dfrac{3}{2}-\dfrac{10}{3}\right)=\dfrac{2}{5}\)
\(\Rightarrow-\dfrac{29}{6}\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)=\dfrac{2}{5}\)
\(\Rightarrow-\dfrac{2}{3}x-\dfrac{3}{5}=-\dfrac{12}{145}\)
\(\Rightarrow-\dfrac{2}{3}x=-\dfrac{12}{145}+\dfrac{3}{5}=\dfrac{15}{29}\)
\(\Rightarrow x=-\dfrac{45}{58}\)
Vậy...
- Tham khảo thanh này để đánh nha bạn ;-;
a) Ta có: \(\dfrac{-3}{2}-\dfrac{2x+3}{4}=-2\)
\(\Leftrightarrow\dfrac{-6-2x-3}{4}=-2\)
\(\Leftrightarrow-2x-9=-8\)
\(\Leftrightarrow-2x=1\)
hay \(x=-\dfrac{1}{2}\)
b) Ta có: \(\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)\left(\dfrac{3}{2}-\dfrac{10}{3}\right)=\dfrac{2}{5}\)
\(\Leftrightarrow\dfrac{-2}{3}x-\dfrac{3}{5}=\dfrac{2}{5}:\dfrac{-11}{6}=-\dfrac{12}{55}\)
\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{21}{55}\)
hay \(x=-\dfrac{63}{110}\)
a, 2/3 - 2/9 + 7/9
b, 7/6 + 3/5 : 6
c, x : 6/25 = 18
d, ( 2/5 + 4/7) : x = 17/5
giúp mik nhé ai nhanh với đúng thì mik tích :D
a, 2/3 - 2/9 + 7/9 = 6/9 - 2/9 + 7/9 = 10/9
b, 7/6 + 3/5 : 6 = 7/6 + 3/5 x 1/6 = 7/6 + 1/10 = 70/60 + 6/10 = 76/10 = 38/5
c, x : 6/25 = 18
x = 18 x 6/25
x = 36/25
d, ( 2/5 + 4/7) : x = 17/5
29/35 : x = 17/5
x = 29/35 : 17/5
x = 29/119
\(a.\dfrac{2}{3}-\dfrac{2}{9}+\dfrac{7}{9}=\dfrac{6}{9}-\dfrac{2}{9}+\dfrac{7}{9}=\dfrac{4}{9}+\dfrac{7}{9}=\dfrac{11}{9}\\ b.\dfrac{7}{6}+\dfrac{3}{5}:6=\dfrac{7}{6}+\dfrac{3}{5}\times\dfrac{1}{6}=\dfrac{7}{6}+\dfrac{1}{10}=\dfrac{70}{60}+\dfrac{6}{60}=\dfrac{76}{60}=\dfrac{19}{15}\\ c.x:\dfrac{6}{25}=18\\ x=18\times\dfrac{6}{25}\\ x=\dfrac{108}{25}\\ d.\left(\dfrac{2}{5}+\dfrac{4}{7}\right):x=\dfrac{17}{5}\\ \dfrac{34}{35}:x=\dfrac{7}{5}\\ x=\dfrac{34}{35}:\dfrac{7}{5}\\ x=\dfrac{34}{49}\)
(x-18)-42=(23-43)-(70+x)
(-x-15) ^2 -19=(-3) ^2 .5
giúp mik với
x - 18 - 42 = 23 - 43 - 70 - x
\(\rightarrow\) 2x = -30
\(\rightarrow\) x = -15
\(\left(-\left(x+15\right)\right)^2\) - 19 = \(3^2\) .5
\(\rightarrow\)\(x^2+30x+225\) - 19 = 45
\(\rightarrow x^2+30x+161=0\)
\(\rightarrow x^2+23x+7x+161=0\)
\(\rightarrow x\left(x+23\right)+7\left(x+23\right)=0\)
\(\rightarrow\left(x+7\right)\left(x+23\right)=0\)
\(\rightarrow\) x = -7 hoặc x = -23
cho x, y,z thỏa: 4z-5y/3 = 5x-3x/4 = 3y-4x/5
cmr x/y/z = 3/4/5
giúp mik với, thank you so much
(2x+2^4).5^3=4.5^5
giúp mình với mình đang gấp
ok:
(2x+24).53=4.55
(2x+24)=4.55:53
(2x+24)=4.52
(2x+24)=100
2x=100-16
2x=84
x=84:2
x=42
tìm các cặp số nguyên x,y: x phần 3 - 1 phần 2= 1 phần y+5
giúp mik với, thankss
tìm x
|2x - 3| ≤ 5
giúp mình với ạ
\(\Leftrightarrow\left\{{}\begin{matrix}2x-3>=-5\\2x-3< =5\end{matrix}\right.\Leftrightarrow-1< =x< =4\)
Tìm x
3/5 - 1/3 x (2,48 + 0,52 )x y :60 : 5 = 1/5
giúp mik với ,mik đang cần gấp
3/5 - 1/3 x (2,48 + 0,52) x y : 60 : 5 = 1/5
1/3 x (2,48+0,52) x y : 60 : 5 = 2/5
1/3 x 3 x y : 60 : 5 = 2/5
y: 60 : 5 =2/5
y: 60 =2/5 x 5
y : 60 =2
y = 2 x 60
y =120
Ta có: \(\dfrac{3}{5}-\dfrac{1}{3}\left(2.48+0.52\right)\cdot y:60:5=\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{3}{5}-\dfrac{1}{3}\cdot3\cdot y\cdot\dfrac{1}{60}\cdot\dfrac{1}{5}=\dfrac{1}{5}\)
\(\Leftrightarrow y\cdot\dfrac{1}{300}=\dfrac{2}{5}\)
hay y=120
cho x+y=7; x^2+y^2=25 tính x^4+y^4; x^5+y^5
giúp mik zới
Ta có \(\left(x+y\right)^2=x^2+2xy+y^2=49\Leftrightarrow xy=\dfrac{49-25}{2}=12\)
\(x^4+y^4=\left(x^2+y^2\right)^2-2x^2y^2=25^2-2\cdot12^2=337\)
Ta có \(x^3+y^3=\left(x+y\right)^3-3xy\left(x+y\right)=7^3-3\cdot12\cdot7=91\)
\(\left(x^2+y^2\right)\left(x^3+y^3\right)=91\cdot25=2275\\ \Leftrightarrow x^5+y^5+2x^2y^2\left(x+y\right)=2275\\ \Leftrightarrow x^5+y^5=2275-2\cdot144\cdot7=259\)