a)2x+7=3x+10

\(\Rightarrow7-10=3x-2x\)

\(\Rightarrow-3=x\)

Vậy x=-3

b)Bạn tự làm nha

c)Bạn làm tương tự câu d nha

d)+)Ta có :\(x+1⋮x+1\left(1\right)\)

+)Theo bài ta có:\(x-3⋮x+1\left(2\right)\)

+)Từ (1) và (2)

\(\Rightarrow\left(x+1\right)-\left(x-3\right)⋮x+1\)

\(\Rightarrow x+1-x+3⋮x+1\)

\(\Rightarrow4⋮x+1\)

\(\Rightarrow x+1\inƯ\left(4\right)=\left\{\pm1;\pm2;\pm4\right\}\)

\(\Rightarrow x\in\left\{-2;0;-3;1;-5;3\right\}\)

Vậy \(x\in\left\{-2;0;-3;1;-5;3\right\}\)

Chúc bn học tốt

\(2x\left(x-2\right)-\left(2-x\right)^2=0\)

\(\Leftrightarrow2x\left(x-2\right)-\left(x-2\right)^2=0\)

\(\Leftrightarrow\left(x-2\right)\left[2x-\left(x-2\right)\right]=0\)

\(\Leftrightarrow\left(x-2\right)\left(x+2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+2=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)

Vậy : \(x\in\left\{-2,2\right\}\)

Tính bằng các thuận tiện nhất: 10/7 x 2/3 + 6/5 : 3/10 - 2/3 x 3/7

trả lời:

10/7 x 2/3 + 6/5 : 3/10 - 2/3 x 3/7=10/7 x 2/3 + 6/5. 10/3 - 2/3 x 3/7=10/7 x 2/3 + 2/3.2- 2/3 x 3/7

=2/3.(10/7+2-3/7)=2/3.3=2

   10/7 x 2/3 + 6/5 : 3/10 - 2/3 x 3/7
= 10/7 x 2/3 + 6/5 x 10/3 - 2/3 x 3/7
= 10/7 x 2/3 + 6/5 x 5 x 2/3 - 2/3 x 3/7
= 10/7 x 2/3 + 6 x 2/3 - 2/3 x 3/7
= 2/3 x (6 + 10/7 - 3/7)
= 2/3 x (6 + 1)
= 2/3 x 7
= 14/3
CHúc bạn học tốt
 

<=> \(x=5\cdot\frac{-6}{10}=-3\)

x=5*6:-10

x=-3

=>x.(-10)=6.5
x.(-10)= 30 
x= 30:(-10)

x= -3 
Vậy, x=-3 
hok tốt 
kb hem

\(a,\dfrac{6.12-6.7}{60}=\dfrac{6\left(12-7\right)}{60}=\dfrac{6.5}{60}=\dfrac{30}{60}=\dfrac{1}{2}\\ b,\dfrac{35.18-35}{\left(-34\right).7}=\dfrac{35\left(18-1\right)}{\left(-34\right).7}=\dfrac{35.17}{\left(-34\right).7}=\dfrac{595}{-238}=\dfrac{-5}{2}\)

\(c,\dfrac{42-11.42}{21.\left(-15\right)}=\dfrac{42\left(1-11\right)}{21.\left(-15\right)}=\dfrac{2.21.\left(-10\right)}{21.\left(-15\right)}=\dfrac{-20}{-15}=\dfrac{4}{3}\)

a, Ta có :

xy=6

yz=-14

xz=-21

=>(xyz)²=1764=>xzy=42 hoặc -42

+)xyz=42

=>z=42:6=7

=>x=-3

=>y=-2

+)xyz=-42

=>z=-7

=>y=2

=>x=3