2/7 + 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
3/7 x 1/2 + 0,5 x 4/7 + 0,125 x 16 + 84 x 1/8
0,75 x 6 + 49 x 3/4 + 3/4 x 24 x 0,75
1/3 x 4/5 + 2/3 + 1/3 +6/5
2/7 + x = 0,75
=>x=0.75 - 2/7 =3/4 - 2/7=13/28
x = 0,75 - 2/7
x = 3/4 - 2/7
=> x = 9/28
( - 0,75 x +5/2 ) . 4/7 - (-1/3)=5/7
0,75 x 26 + 49 x 3/4 + 3/4 x24 + 0,75
3/7 x 1/2 + 0,5 x 4/7 + 0,125
1/3 x 4/5 + 2/3 + 1/3 + 6/5 x 16 + 84 x 1/8
Giúp mk giải chích xác
a) \(0,75\times26+49\times\frac{3}{4}+\frac{3}{4}\times24+\) \(0,75\)
\(=\) \(0,75\times\left(26+1\right)+\frac{3}{4}\times\left(49+24\right)\)
\(=\) \(\frac{3}{4}\times27+\frac{3}{4}\times73\)
\(=\) \(\frac{3}{4}\times\left(27+73\right)\)
\(=\)\(\frac{3}{4}\times100=75\)
b) câu b,c làm tương tự
0,75.x -2/5x= 7/20
\(0,75.x-\frac{2}{5}.x=\frac{7}{20}\)
=> \(\frac{3}{4}.x-\frac{2}{5}.x=\frac{7}{20}\)
=> \(x\left(\frac{3}{4}-\frac{2}{5}\right)=\frac{7}{20}\)
=> \(x.\frac{7}{20}=\frac{7}{20}\)
=> x=1
tìm x
( 3/5 . x - 0,75 ) : 3/7 = 2 4/5
\(\left(\frac{3}{5}.x-0,75\right):\frac{3}{7}=2\frac{4}{5}\)
\(\Leftrightarrow\)\(\frac{3}{5}.x-0,75=2\frac{4}{5}.\frac{3}{7}=1\frac{1}{5}\)
\(\Leftrightarrow\)\(\frac{3}{5}.x=1\frac{1}{5}+0,75=1,95\)
\(\Leftrightarrow\)\(x=1,95:\frac{3}{5}=3,25\)
Vậy....
4 / 7 x X + 3 / 7 - 0,75 x X = 1,25
Thay X \(=1,25\) vào biểu thức \(\dfrac{4}{7}\) x \(X+\dfrac{3}{7}-0,75\) x X ta có:
\(\dfrac{4}{7}\) x \(1,25+\dfrac{3}{7}-0,75\) x \(1,25\)
\(=\dfrac{5}{7}+\dfrac{3}{7}-\dfrac{15}{16}\)
\(=\dfrac{80}{112}+\dfrac{48}{112}-\dfrac{105}{112}\)
\(=\dfrac{80+48-105}{112}=\dfrac{23}{112}\)
Vậy X\(=1,25\) giá trị biểu thức \(\dfrac{4}{7}\) x \(X+\dfrac{3}{7}-0,75\) x X là: \(\dfrac{23}{112}\)
5/6.x+1/2-1/3.x=0,75.x-7/8
jup mik vs thank
\(\frac{5}{6}x+\frac{1}{2}-\frac{1}{3}x=0,75x-\frac{7}{8}\)
\(\frac{5}{6}x-\frac{1}{3}x-0,75x=-\frac{7}{8}-\frac{1}{2}\)
\(\frac{5}{6}x-\frac{1}{3}x-\frac{3}{4}x=-\frac{11}{8}\)
\(\frac{1}{2}x-\frac{3}{4}x=-\frac{11}{8}\)
\(-\frac{1}{4}x=-\frac{11}{8}\)
\(x=-\frac{11}{8}:-\frac{1}{4}\)
\(x=\frac{11}{2}\)