3.(-4)^3-2.(-5)+(-7)^2.(-6)=3.-64-(-10)+49.(-6)=(-192)-(-10)+(-294)=(-182)+(-294)=(-476)

(5).(-26-25)+(-4).(-51)=5.(-51)+204=(-255)+204=-51

34.(47-75)+47.(75-34)=34.(-28)+47.41=(-952)+1927=975

(-25).(75-45)-75.(45-25)=(-25).30-75.20=(-750)-1500=-2250

thankyou verry much

75%\(x\) - \(\frac32\): \(\frac54\) = 2\(\frac12\) + 25%

0,75\(x\) - \(\frac32\times\frac45\) = 2,5 + 0,25

0,75\(x\) - \(\frac65\) = 2,75

0,75\(x\) - 1,2 = 2,75

0,75\(x\) = 2,75 + 1,2

0,75\(x\) = 3,95

\(x\) = 3,95 : 0,75

\(x\) = \(\frac{79}{15}\)

Vậy \(x=\frac{79}{15}\)

\(a.3x-75=45+3\times\left(-25\right)\)

\(3x-75=45+\left(-75\right)\)

\(3x-75=-30\)

\(3x=-30+75\)

\(3x=45\)

\(x=45:3\)

\(x=15\)

Vậy \(x=15\)

\(b.\frac{x}{3}=\frac{2}{3}+\frac{-1}{7}\)

\(\frac{x}{3}=\frac{11}{21}\)

\(\Rightarrow\frac{x\times7}{21}=\frac{11}{21}\)

\(\Rightarrow x\times7=11\)

\(x=11:7\)

\(x=\frac{11}{7}\)

\(\Rightarrow\)\(x\)không thỏa mãn

Vậy \(x\in\varnothing\)

a) 3x-75=45+3.(-25)

\(\Rightarrow3x-75=45+\left(-75\right)\)

\(\Rightarrow3x-75-45+75=0\)

\(\Rightarrow3x-45-75+75=0\)

\(\Rightarrow3x-45=0\)

\(\Rightarrow3x=45\)

\(\Rightarrow x=\frac{45}{3}=15\)

Vậy: \(x=15\)

(20-3.x):5=55-51

(20-3.x):5=4

20-3.x=4.5

20-3.x=20

3.x=20-20

3.x=0

x=0:3

x=0

không đc đừng ném mik nha

Câu b:

71 + (26 - 3\(x\)) : 5 = 75

(26 - 3\(x\)) : 5 = 75 - 71

(26 - 3\(x\)) : 5 = 4

(26 - 3\(x\)) = 4 x 5

26 - 3\(x\) = 20

3\(x\) = 26 - 20

3\(x\) = 6

\(x=6:3\)

\(x\) = 2

Vậy \(x=2\)

giải

a)51+(20-3.x):5=55

(20-3.x):5=55-51

(20-3x):5=4

20-3x=5.4

20-3x=20

3x=20-20

3x=0

x=0:3

x=0

b)71+(26-3.x):5=75

(26-3.x):5=75-71

(26-3x):5=4

26-3x=4.5

26-3x=20

3x=26-20

3x=6

x=6:3

x=2

mik chỉ giải đc 2 câu đầu thôi

​mong bạn thông cảm

mk giải tiếp câu c

(x-6)^2=5^2

x-6=5

x=5+6

x=11

a, 21(x - 3) < 0

=> x - 3 < 0

=> x < 3

b, (x^2 + 1)(x + 2) < 0

=> x + 2 < 0

=> x < 2

c, (x + 2)(x - 3) = 0

=> x + 2 = 0 hoặc x - 3 = 0

=> x = - 2 hoặc x = 3

\(\frac{2}{x}=\frac{y}{15}=\frac{-25}{-75}\)

=> \(\frac{2}{x}=\frac{y}{15}=\frac{1}{3}\)

=> \(\hept{\begin{cases}\frac{2}{x}=\frac{1}{3}\\\frac{y}{15}=\frac{1}{3}\end{cases}}\Rightarrow\hept{\begin{cases}x=6\\y=5\end{cases}}\)

Ta có :

\(\frac{2}{x}=\frac{y}{15}=\frac{-25}{-75}=\frac{1}{3}\)

+) \(\frac{2}{x}=\frac{1}{3}\Leftrightarrow x=6\)

+) \(\frac{y}{15}=\frac{1}{3}\Leftrightarrow y=5\)

c) !2-x!+2=x

!x-2!=x-2

đúng với mọi x>=2

Tập ghi có dấu đi bạn ei

ghi như thế méo ai hiểu đâu

và......kết bạn nha!

>< :3 :))

d)=(-75)+25+75

= 0+25=25

b)(-2016).97+2016.(-13)

= 2016.(-97)+2016.(-13)

=2016.(-97-13)

=2016.(-100)

=-201600

Bài 1:

\(\left(-\dfrac{72}{40}-\dfrac{144}{60}-2\dfrac{1}{3}\right):\left(\dfrac{45}{100}-\dfrac{25}{60}+-\dfrac{75}{25}\right)\)

\(=\left(-\dfrac{9}{5}-\dfrac{12}{5}-\dfrac{7}{3}\right):\left(\dfrac{9}{20}-\dfrac{5}{12}+-3\right)\)

\(=\left(-\dfrac{27}{15}-\dfrac{36}{15}-\dfrac{21}{15}\right):\left(\dfrac{27}{60}-\dfrac{25}{60}+-3\right)\)

\(=\left(-\dfrac{28}{5}\right):\left(-\dfrac{89}{30}\right)\)

\(=\left(-\dfrac{28}{5}\right).\left(-\dfrac{30}{89}\right)\)

\(=\dfrac{168}{89}\)