1 và 3/8 + 1/8 : (0,75 - 1/2) - 25% x 1/2
A= 7/12 +5/12 : 6 - 11/36
D = 1 và 3/8 + 1/8 : (0,75 - 1/2 ) -25% nhân 1/2
\(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}=\dfrac{21}{36}+\dfrac{5}{12}.\dfrac{1}{6}-\dfrac{11}{36}=\dfrac{5}{18}+\dfrac{5}{12}.\dfrac{1}{6}=\dfrac{20}{72}+\dfrac{5}{72}=\dfrac{25}{72}\)
\(B=1\dfrac{3}{8}+\dfrac{1}{8}:\left(0,75-\dfrac{1}{2}\right)-25\%.\dfrac{1}{2}=\dfrac{11}{8}+\dfrac{1}{8}:\dfrac{1}{4}-\dfrac{1}{8}=\dfrac{5}{4}+\dfrac{1}{2}=\dfrac{7}{4}\)
a) Ta có: \(A=\dfrac{7}{12}+\dfrac{5}{12}:6-\dfrac{11}{36}\)
\(=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}\)
\(=\dfrac{42+5-22}{72}\)
\(=\dfrac{25}{72}\)
b) Ta có: \(A=1\dfrac{3}{8}+\dfrac{1}{8}:\left(0.75-\dfrac{1}{2}\right)-25\%\cdot\dfrac{1}{2}\)
\(=\dfrac{11}{8}+\dfrac{1}{8}:\dfrac{1}{4}-\dfrac{1}{4}\cdot\dfrac{1}{2}\)
\(=\dfrac{11}{8}-\dfrac{1}{8}+\dfrac{1}{2}\)
\(=\dfrac{10}{8}+\dfrac{1}{2}\)
\(=\dfrac{5}{4}+\dfrac{2}{4}=\dfrac{7}{4}\)
tính
D = 1 3/8 + 1/8 : ( 0,75 - 1/2 ) - 25% . 1/2
\(D=\frac{13}{8}+\frac{1}{8}:\left(0,75-\frac{1}{2}\right)-25\%.\frac{1}{2}\)
\(D=\frac{13}{8}+\frac{1}{8}:\left(\frac{3}{4}-\frac{1}{2}\right)-\frac{1}{4}X\frac{1}{2}\)
\(D=\frac{13}{8}+\frac{1}{8}:\frac{1}{4}-\frac{1}{4}X\frac{1}{2}\)
\(D=\frac{13}{8}+\frac{4}{8}-\frac{1}{8}\)
\(D=\frac{17}{8}-\frac{1}{8}\)
\(D=2\)
TÍNH
\(D=\frac{13}{8}+\frac{1}{8}\div\left(0,75-1,2\right)-25\%.\frac{1}{2}\)
\(D=\frac{13}{8}+\frac{1}{8}\div\frac{-9}{20}-\frac{1}{4}.\frac{1}{2}\)
\(D=\frac{13}{8}+\frac{-5}{18}-\frac{1}{8}\)
\(D=\frac{13}{8}-\frac{1}{8}+\frac{-5}{18}\)
\(D=\frac{3}{2}+\frac{-5}{18}\)
\(D=\frac{11}{9}\)
CHÚC BN HỌC TỐT !!!!!
1 8/3 + 1/8 : (0,75 - 1/2 ) - 25% . 1/2
= ? cac ban
18/3+1/8÷(3/4-1/2)-1/4.1/2
18/3+1/8÷-1/4-1/4.1/2
1/8.-4/1-1/4.1/2
-4/8-1/8
-5/8
a) x : 4/5 = 28/5 : 5/4
b) 8/15 . x + 5/7 = 2/21
c) 7/8-1/6.x = 1/4
d) [ 3 và 1/2 - 2.x ].4/3=7 và 1/3
e) | x-1/2 |-3/4=0
f) [2.x +1/3].[5/7-x]=0
g) x-2/121=-11/6.6/7
h) (-3).x +0,75.x=-1 và 3/4
i) [x+1/5]^2 + 17/25 = 26/25
j) |2x-1| = (-4)^2
1. tính giá trị của các biểu thức sau:
a,(-2).4.5.38.(-25)
b, 1/3+3/8-7/12
c,-5/8 .5/12+-5/8.7/12 +2 1/8( 2 1/8 là hỗn số nhé ahihi)
d.(-5 /24+0,75+7/12):(-2 1/8) (-2 1/8 là hỗn số nhé)
2. tìm X biết
a,x-2/5= 0,24
b, 2/3.x+1/12=1/10
c,(3 1/2- 2x ). 1 1/3= 7 1/3 (3 1/2; 1 1/3; 7 1/3 là hỗn số)
1 a)38000 b)1/8 c)3/2 d)9/17
2 a) 0.64 b)0.025 c)-1
Bài giải:
Câu 1: a, \(\left(-2\right).4.5.38.\left(-25\right)\)
\(=\left[\left(-2\right).5\right].\left[4.\left(-25\right)\right].38\)
\(=\left(-10\right).\left(-100\right).38\)
\(=1000.38=38000\)
b,\(\frac{1}{3}+\frac{3}{8}-\frac{7}{12}\)
\(=\left(\frac{1}{3}+\frac{3}{8}\right)-\frac{7}{12}\)
\(=\frac{17}{24}-\frac{7}{12}=\frac{1}{8}\)
c, \(\frac{-5}{8}.\frac{5}{12}+\frac{-5}{8}.\frac{7}{12}+2\frac{1}{8}\)
\(=\frac{-5}{8}.\left(\frac{5}{12}+\frac{7}{12}\right)+\frac{17}{8}\)
\(=\frac{-5}{8}.1+\frac{17}{8}\)
\(=\frac{3}{2}\)
Câu 2: a, \(x-\frac{2}{5}=0,24\)
\(x-0,4=0,24\)
\(x=0,24+0,4\)
\(\Rightarrow x=0,64\left(\frac{16}{25}\right)\)
b,\(\frac{2}{3}.x+\frac{1}{12}=\frac{1}{10}\)
\(\frac{2}{3}.x=\frac{1}{10}-\frac{1}{12}\)
\(\frac{2}{3}.x=\frac{1}{60}\)
\(x=\frac{1}{60}:\frac{2}{3}\)
\(\Rightarrow x=\frac{1}{40}\)
c, \(\left(3\frac{1}{2}-2x\right).1\frac{1}{3}=7\frac{1}{3}\)
\(\frac{7}{2}-2x=\frac{22}{3}:\frac{4}{3}\)
\(\frac{7}{2}-2x=\frac{11}{2}\)
\(2x=\frac{7}{2}-\frac{11}{2}\)
\(2x=-2\)
\(\Rightarrow x=-2:2\)
\(x=-1\)
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
Đơn giản biểu thức: \(B=\frac{0,75-30\%+\frac{3}{7}+\frac{3}{13}}{2,75-2,2+1\frac{4}{7}+3\frac{2}{3}}\)
Nhanh tay!!!
Và tìm x: \(\frac{-2}{x}=\frac{-x}{8}=\frac{-x}{\frac{8}{25}}\)
Trả lời:
\(B=\frac{0,75-30\%+\frac{3}{7}+\frac{3}{13}}{2,75-2,2+1\frac{4}{7}+3\frac{2}{3}}\)
\(B=\frac{\frac{3}{4}-\frac{3}{10}+\frac{3}{7}+\frac{3}{13}}{\frac{11}{4}-\frac{11}{5}+\frac{11}{7}+\frac{11}{3}}\)
\(B=\frac{2019}{1820}\div\frac{2431}{420}\)
\(B=\frac{2019}{1820}\times\frac{420}{2431}\)
\(B=\frac{6057}{31603}\)
A,. 1 13/15 .0,75 -(11/20+25%):7/5
B, (2/3)^2:(-8)-(-1/4+9/20):1 4/5
Giúp em với ạ 🥺
= 4/9 : -8 - (-1/4 + 9/20) : 14/5
= 4/9 : -8 - 1/5 : 14/5
= -1/18 - 1/5 : 14/5
= -1/18 - 1/14
= -8/63
1. Tính ( Phân số )
1) -5/24+16/27+0,75
2)-4/12+6/7+8/24
3)9/18+-7/12+-16/-32
4)5/-8+14/25+-6/10
2. Tìm x , biết :
1) 1/3 + 1/33 < x/210 < -4/-7 + 3/5 + -2/3 (x thuộc Z )
2) 5/3 + -14/3 < x < 1/5 +18/10 ( x thuộc Z )
Bài 1:
1: =-5/24+16/27+3/4
=-5/24+18/24+16/27
=13/24+16/27
=117/216+128/216=245/216
2: =-1/3+1/3+6/7=6/7
3: \(=\dfrac{1}{2}-\dfrac{7}{12}+\dfrac{1}{2}=1-\dfrac{7}{12}=\dfrac{5}{12}\)
4: \(=-\dfrac{5}{8}+\dfrac{14}{25}-\dfrac{6}{10}=\dfrac{-125+112-120}{200}=\dfrac{-133}{200}\)