Tìm x biết: x ÷ 2 + 6 + x = 0,75
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
Bài 1: Tìm x, biết:
a) (0,75 x + 5/2) - 4/7 - (-1/3) = -5/6
b) (4 x - 9) . (2,5 + -7/3 x) = 0
Thanks
\(a,\left[0,75x+\frac{5}{2}\right]-\frac{4}{7}-\left[-\frac{1}{3}\right]=-\frac{5}{6}\)
\(\Leftrightarrow\left[0,75x+\frac{5}{2}\right]-\frac{4}{7}+\frac{1}{3}=-\frac{5}{6}\)
\(\Leftrightarrow\left[0,75x+\frac{5}{2}\right]=-\frac{5}{6}-\frac{1}{3}+\frac{4}{7}\)
\(\Leftrightarrow0,75x+\frac{5}{2}=-\frac{25}{42}\)
\(\Leftrightarrow0,75x=-\frac{65}{21}\Leftrightarrow x=-\frac{260}{63}\)
\(b,\left[4x-9\right]\left[2,5+-\frac{7}{3}x\right]=0\)
\(\Leftrightarrow\orbr{\begin{cases}4x-9=0\\2,5+-\frac{7}{3}x=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{9}{4}\\x=\frac{15}{14}\end{cases}}\)
Vậy \(x\in\left\{\frac{9}{4};\frac{15}{14}\right\}\)
Tham khảo nhé phamthiminhanh
a) \(\left(0,75x+\frac{5}{2}\right)-\frac{4}{7}-\left(-\frac{1}{3}\right)=-\frac{5}{6}\)
=> \(0,75x+\frac{5}{2}-\frac{4}{7}+\frac{1}{3}=-\frac{5}{6}\)
=> \(0,75x=-\frac{5}{6}-\frac{5}{2}+\frac{4}{7}-\frac{1}{3}\)
=> \(0,75x=-\frac{65}{21}\)
=> \(x=-\frac{260}{63}\)
b) \(\left(4x-9\right)\left(2,5+-\frac{7}{3}x\right)=0\)
=> \(10x-\frac{28}{3}x^2-22,5+21x=0\)
=> \(-\frac{28}{3}x^2+31x-22,5=0\)
=> Phần còn lại bạn tự giải tiếp nhé!
TÌM X BIẾT
3 phần 4 : x phần 6 = 0,75
\(\frac{3}{4}:\frac{x}{6}=0.75\)
\(\frac{3}{4}\cdot\frac{6}{x}=\frac{3}{4}\)
\(\frac{6}{x}=\frac{3}{4}:\frac{3}{4}\)
\(\frac{6}{x}=1\)
\(x=6\)
3/4 : x/6 = 0,75
x/6 = 0,75 : 0,75
x/6 = 1
x = 6
Hok tốt !!!
~~~ Mon ~~~
\(\frac{3}{4}:\frac{x}{6}=0,75\)
\(\frac{3}{4}:\frac{x}{6}=\frac{3}{4}\)
\(\frac{x}{6}=\frac{3}{4}:\frac{3}{4}\)
\(x:6=1\)
\(x=1x6\)
\(x=6\)
Vậy x = 6
\(\frac{7}{12}x+0,75=-2\frac{1}{6}=-\frac{13}{6}\)
\(=>\frac{7}{12}x=-\frac{13}{6}-0,75=-\frac{13}{6}-\frac{3}{4}=-\frac{35}{12}\)
\(=>x=-\frac{35}{12}:\frac{7}{12}=-\frac{35}{12}.\frac{12}{7}=-\frac{35}{7}=-5\)
Vậy x=-5
\(-1<\frac{x}{4}<\frac{1}{2}\)
\(<=>-\frac{4}{4}<\frac{x}{4}<\frac{2}{4}\)
<=>-4<x<2
<=>x E {-3;-2;-1;0;1}
Vậy.......................
a) Tìm x, biết:
\(\frac{7}{12}x+0,75=-2\frac{1}{6}\)
b)Tìm các giá trị nguyên của x sao cho:
\(-1< \frac{x}{4}< \frac{1}{2}\)
\(a)\frac{7}{12}x+0,75=-2\frac{1}{6}\)
\(\Rightarrow\frac{7}{12}x+\frac{3}{4}=-\frac{13}{6}\)
\(\Rightarrow\frac{7}{12}x=-\frac{13}{6}-\frac{3}{4}\)
\(\Rightarrow\frac{7}{12}x=-\frac{26}{12}-\frac{9}{12}\)
\(\Rightarrow\frac{7}{12}x=-\frac{35}{12}\)
\(\Rightarrow x=-\frac{35}{12}:\frac{7}{12}\)
\(\Rightarrow x=-\frac{35}{12}.\frac{12}{7}\)
\(\Rightarrow x=-5\)
\(b)-1< \frac{x}{4}< \frac{1}{2}\)
\(\Rightarrow-\frac{4}{4}< \frac{x}{4}< \frac{2}{4}\)
\(\Rightarrow-4< x< 2\)
\(\Rightarrow x\in\left\{-3;-2;-1;0;1\right\}\)
Chúc bạn học tốt !!!
\(\frac{7}{12}x+0,75=-2\frac{1}{6}\)
\(\frac{7}{12}x=-\frac{13}{6}-\frac{3}{4}\)
\(\frac{7}{12}x=\frac{-35}{12}\)
\(x=\frac{-35}{12}:\frac{7}{12}\)
\(x=-5\)
b) \(-1< \frac{x}{4}< \frac{1}{2}\)
\(\frac{-4}{4}< \frac{x}{4}< \frac{2}{4}\)
\(\Rightarrow-4< x< 2\)
mà \(x\in Z\) nên \(x\in\left\{-3;-2;\pm1;0\right\}\)
Tìm x, biết:
x +3x : 2 = 0,75
x +3x :2 =0,75
=>x +1,5x = 0,75
=>(1+1,5)x = 0,75
=>2,5x =0,75
=>x =0,3
(x + 3x) : 2 = 0,75
=> 4x = 0.75 . 2
=> 4x = 1,5
=> x = 1,5 : 4
\(x+3x\div2=0,75\)
\(\left(x+3x\right)=0,75\cdot2\)
\(1x+3x=1,5\)
\(4x=1,5\)
\(x=1,5\div4\)
\(x=0,375\)
Tìm x biết 3.x+25%.x=-0,75
3 . x + 25% . x = -0,75
3 . x + 0,25 . x = -0,75
x . ( 3 + 0,25 ) = -0,75
x . 3,25 = -0,75
x = -0,75 : 3,25
x = \(-\frac{3}{13}\)
bài 1
2/5-3/5:(0,75+30%)
bài 2:tìm x
a) x/6= -11/3
b) 16/5 của x là 48
Bài 1
2/5 - 3/5 : (0,75 + 30%)
= 2/5 - 3/5 : 21/20
= 2/5 - 4/7
= -6/35
‐--------------------
Bài 2
a) x/6 = -11/3
x = -11/3 . 6
x = -22
b) 16/5 của x là 48
x = 48 : 16/5
x = 15
bài1
2/5-3/5:(0,75+30%)=2/5-3/5:(75/100+30/100)
=2/5-3/5:105/100
=2/5-3/5:21/20
= 2/5-3/5. 20/21
=2/5-1/1.4/7
=2/5-4/7
=2/5+-4/7
=14/35+-20/35
=34/35
Tìm x biết − 1 4 + x + 0 , 75 = 3 1 2
− 1 4 + x + 0 , 75 = 3 1 2 → x = 7 2 − 3 4 + 1 4 → x = 3