ko bt ccc

pt vt lại:

\(\dfrac{x+4}{x^2-3x+2}+\dfrac{x+1}{x^2-4}+5=\dfrac{2x+5}{x^2-4x+5}\)

pt này đk?

a) \(\left(x+2y\right)^2=x^2+2.x.2y+\left(2y\right)^2=x^2+4xy+4y^2\)

b) \(\left(3-x\right).\left(3+x\right)=9+3x-3x-x^2=9-x^2=3^2-x^2\)

c) \(\left(5-x\right)^2=5^2-2.5.x+x^2=25-10x+x^2\)

d) \(\left(3+y\right)^2=3^2+2.3.y+y^2=9+6y+y^2\)

a) x²+4xy+4y² b)x(9-x²) = 9x-x³ c)25-10x+x² d)9+6y+x²

​

\(\dfrac{25}{2-x}=\dfrac{5}{3}\\ \Rightarrow25.3=5.\left(2-x\right)\\ \Rightarrow75=10-5x\\ \Rightarrow-5x=-65\\ \Rightarrow13\)

\(\Rightarrow5x=-65\\ \Rightarrow-13\)

mik sửa lại

\(\dfrac{25}{2-x}=\dfrac{5}{3}\)

\(\Leftrightarrow\dfrac{75}{3\left(2-x\right)}=\dfrac{5\left(2-x\right)}{3\left(2-x\right)}\)

\(\Leftrightarrow75=10-5x\)

\(\Leftrightarrow5x=10-75\)

\(\Leftrightarrow5x=-65\)

\(\Leftrightarrow x=\dfrac{-65}{5}=-13\)

5.(2.x-3)=70-45=25

2.x-3=5

2.x=5+3=8

x=8/2=4

70 - 5 . ( 2.x - 3 ) = 45

5( 2x -3 ) = 70 - 45

5( 2x-3 ) = 25

2x-3 = 5

2x = 8

x = 4

70 - 5 . ( 2 . x - 3 ) = 45

5 . ( 2 . x - 3 ) = 70 - 45

5 . ( 2 . x - 3 ) = 25

2 . x - 3 = 25 : 5

2 . x - 3 = 5

2 . x = 5 + 3

2 . x = 8

x = 8 : 2

x = 4

\(2.x+2^2.x-10=5^2+3^2\)

\(\Leftrightarrow2.x+4.x-10=25+9\)

\(\Leftrightarrow2.x+4.x-10=34\)

\(\Leftrightarrow x.\left(4+2\right)-10=34\)

\(\Rightarrow x.\left(4+2\right)=34+10=44\)

\(\Rightarrow x=44:6=7\)(dư 2)

\(x+\frac{1}{2}=2+\frac{x}{4}\)

\(\Leftrightarrow\frac{4x+2}{4}=\frac{8+x}{4}\)

\(\Rightarrow4x+2=8+x\)

\(\Leftrightarrow4x-x=8-2\)

\(\Leftrightarrow3x=6\Leftrightarrow x=2\)

không biết bạn viết đề như nào z

hay thế này ?????

\(\frac{x+1}{2}=\frac{2+x}{4}\)

\(\Leftrightarrow4x+4=4+2x\)

\(\Leftrightarrow4x-2x=4-4\)

\(\Leftrightarrow2x=0\Leftrightarrow x=0\)

\(\frac{x+1}{2-x}=\frac{-2}{-5}\)(\(x\ne2\))

\(\Leftrightarrow\frac{x+1}{2-x}=\frac{2}{5}\)

\(\Leftrightarrow4-2x=5x+5\)

\(\Leftrightarrow-2x-5x=5-4\)

\(\Leftrightarrow-7x=1\Leftrightarrow x=-\frac{1}{7}\)

a: \(\Leftrightarrow5x=20\)

hay x=4

b: \(\Leftrightarrow x+7=24\)

hay x=17

1) \(5x-7=13\Rightarrow5x=13+7=20\Rightarrow x=20:5=4\)

2) \(\Rightarrow3\left(x+7\right)=95-23=72\)

\(\Rightarrow x+7=72:3=24\Rightarrow x=24-7=17\)

3) \(\Rightarrow2x+27=343\Rightarrow2x=343-27=316\Rightarrow x=316:2=158\)

+) 5x-7=13

5x=13+7

5x=20

x=20:5

x=4

+) 95-3(x+7)=23

3(x+7)=95-23

3(x+7)=72

x+7=72:3

x+7=24

x=24-7

x=17

+) 2x+3\(^2\).3=7\(^5\):7\(^2\)

2x+3\(^3\)=7\(^3\)

2x+27=343

2x=343-27

2x=316

x=316:2

x=158