- 3,5 {3/-4
-5/2 : 3/-4
(3/5*7^2-〖3,5〗^6+3/5*3^9) / (3/4*7^2-3/4*5^7+3/4*3^9 )
a)|-x+2/5|+1/2=3,5 b)21/5+3:|x/4-2/3|=6
c)7,5-3|5-2x|=-4,5 d)1/3-|5/4-2x|=1/4
e)21/5+3:|x/4-2/3|=6
a)|-x+2/5|+1/2=3,5 b)21/5+3:|x/4-2/3|=6
c)7,5-3|5-2x|=-4,5 d)1/3-|5/4-2x|=1/4
e)21/5+3:|x/4-2/3|=6
a: Ta có: \(\left|\dfrac{2}{5}-x\right|+\dfrac{1}{2}=3.5\)
\(\Leftrightarrow\left|x-\dfrac{2}{5}\right|=3\)
\(\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{2}{5}=3\\x-\dfrac{2}{5}=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{17}{5}\\x=-\dfrac{13}{5}\end{matrix}\right.\)
b: Ta có: \(\dfrac{21}{5}+3:\left|\dfrac{x}{4}-\dfrac{2}{3}\right|=6\)
\(\Leftrightarrow3:\left|\dfrac{1}{4}x-\dfrac{2}{3}\right|=6-\dfrac{21}{5}=\dfrac{9}{5}\)
\(\Leftrightarrow\left|\dfrac{1}{4}x-\dfrac{2}{3}\right|=\dfrac{5}{3}\)
\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{4}x-\dfrac{2}{3}=\dfrac{5}{3}\\\dfrac{1}{4}x-\dfrac{2}{3}=-\dfrac{5}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{4}x=\dfrac{7}{3}\\\dfrac{1}{4}x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{28}{3}\\x=-4\end{matrix}\right.\)
Bỏ dấu ngoặc rồi tính
a) (5,1-3,5) - (3,5+5,1)
b) -(271,5+381)+5,261-(1-381)
c) (3/4+3/4)-(-3/4+2/5)
a,\(\left(5,1-3,5\right)-\left(3,5+5,1\right)\)
\(=5,1-3,5-3,5-5,1\)
\(=\left[5,1-5,1\right]\)\(-\)\(\left[3,5-3,5\right]\)
\(=0-0\)
\(=0\)
b,c bn tự làm nha
Tính
(2/5)^6 : (2/5)^4
(3/16)^2 : (9/8)^2
(2/7 - 1/2)^2
Tìm x , biết
x/1,5 = 4/3
2/9 = x/-72
x: -3/8 = 1/3
|x| = 3,5
|x - 1| = 3,5
Tính
(3/7 + 1/2)^2
(1+2/3 - 1/4)x(4/5 - 3/4)^2
\(\left(\frac{2}{5}\right)^6:\left(\frac{2}{5}\right)^4=\left(\frac{2}{5}\right)^2=\frac{4}{25}\)
\(\left(\frac{3}{16}\right)^2:\left(\frac{9}{8}\right)^2=\frac{1}{12}\)
\(\left(\frac{2}{7}-\frac{1}{2}\right)^2=\frac{9}{196}\)
\(\frac{\frac{3}{5}\cdot7^2-3,5^6+\frac{3}{5}\cdot3^9}{\frac{3}{4}\cdot7^2-\frac{3}{4}\cdot5^7+\frac{3}{4}\cdot3^9}\)
3/4 nhân x - 2/3=5/4
3/5 - x = 0,5
1,25 nhân x - 3,5 = 1,5
3/4 nhân x - 2/3 = 5/4
3/4 nhân x = 5/4 - 2/3
3/4 nhân x = 3/1
x = 3/4 : 3/1
x = 1/12
3/5 - x = 0,5
3/5 - x = 1/2
x = 3/5 - 1/2
x = 1/10
1,25 nhân x - 3,5 = 1,5
1,25 nhân x = 1,5 + 3,5
1,25 nhân x = 5
x = 1,25 : 5
x = 0,25
4+2=3
5+2=3,5
6+2=4
7+2=?
4+2=3
5+2=7
6+2=4
7+2=4.5
Đúng thì k mình nha!
Bài 1: Tính
1) 2,75 - 5/6 × 2/5
2) 1,25 - ( 5/6 - 0,75 ) - 3/5
3) 4/9 × 0,75 + 8/5 + 3,125
4) 1,125 - 4/7 - 0,12
5) (1/3 + 0,4) × 3,5 + (1/6 + 0,75) × 6/5
Bài 2: Tìm x, biết
1) 1,25 × x - 0,75 = 1/3
2) x - 0,25 × 2/9 = 1/6 × 0,5
3) 3,375 × 8/9 - x = 5/6
4) 1,75 × 4/5 + x = 4,5
1) 2,75 - 5/6 × 2/5 = 2,75 - (5/6) × (2/5) = 2,75 - 1/3 = 2,75 - 0,33 = 2,42
2) 1,25 - (5/6 - 0,75) - 3/5 = 1,25 - (5/6 - 0,75) - 3/5 = 1,25 - (5/6 - 3/4) - 3/5 = 1,25 - (5/6 - 9/12) - 3/5 = 1,25 - (10/12 - 9/12) - 3/5 = 1,25 - 1/12 - 3/5 = 1,25 - 0,08 - 0,6 = 1,25 - 0,68 = 0,57
3) 4/9 × 0,75 + 8/5 + 3,125 = (4/9) × 0,75 + 8/5 + 3,125 = 0,44 + 8/5 + 3,125 = 0,44 + 1,6 + 3,125 = 0,44 + 4,725 = 5,165
4) 1,125 - 4/7 - 0,12 = 1,125 - (4/7) - 0,12 = 1,125 - 0,57 - 0,12 = 0,435 - 0,12 = 0,315
5) (1/3 + 0,4) × 3,5 + (1/6 + 0,75) × 6/5