x-5=14

Bài 1:

a) Ta có: \(82-7\left(3x-4\right)=47\)

\(\Leftrightarrow82-21x+28-47=0\)

\(\Leftrightarrow-21x+63=0\)

\(\Leftrightarrow-21x=-63\)

hay x=3(nhận)

Vậy: x=3

b) Ta có: \(97+4\left(5x-7\right)=129\)

\(\Leftrightarrow97+20x-28-129=0\)

\(\Leftrightarrow20x-60=0\)

\(\Leftrightarrow20x=60\)

hay x=3(nhận)

Vậy: x=3

c) Ta có: \(\left(7x-13\right)\cdot27-12=15\)

\(\Leftrightarrow189x-351-12-15=0\)

\(\Leftrightarrow189x-378=0\)

\(\Leftrightarrow189x=378\)

hay x=2(nhận)

Vậy: x=2

d) Ta có: \(\left(2x+3\right)\cdot13+23=140\)

\(\Leftrightarrow26x+39+23-140=0\)

\(\Leftrightarrow26x-78=0\)

\(\Leftrightarrow26x=78\)

hay x=3(nhận)

Vậy: x=3

đ) Ta có: \(52x+8x-5x=70\)

\(\Leftrightarrow55x=70\)

\(\Leftrightarrow x=\frac{70}{55}\)(loại)

Vậy: x∈∅

e) Ta có: \(19x-3x-x=60\)

\(\Leftrightarrow15x=60\)

hay x=4(nhận)

Vậy: x=4

g) Ta có: \(7\left(3x+1\right)-5\left(3x+1\right)=74\)

\(\Leftrightarrow2\left(3x+1\right)=74\)

\(\Leftrightarrow3x+1=37\)

\(\Leftrightarrow3x=36\)

hay x=12(nhận)

Vậy: x=12

h) Ta có: \(5\left(3x-1\right)+7\left(3x-1\right)=96\)

\(\Leftrightarrow12\left(3x-1\right)=96\)

\(\Leftrightarrow3x-1=8\)

\(\Leftrightarrow3x=9\)

hay x=3(nhận)

Vậy: x=3

\(5^x.5^2=5^{40}\)

\(\Rightarrow5^x=5^{40}:5^2=5^{38}\)

=> x = 38

\(5^x\cdot5^2=5^{40}\)

\(\Leftrightarrow x+2=40\)

hay x=38

`5x-52=10`

`5x=10+52`

`5x=62`

`x=62:5`

`x=62/5=12,4`

`5x-52=10`

`5x=10+52`

`5x=62`

`x=62/5`

\(125:5^x+5^2=26\)

\(\Rightarrow125:5^x+25=26\)

\(\Rightarrow125:5^x=26-25\)

\(\Rightarrow125:5^x=1\)

\(\Rightarrow5^x=125:1\)

\(\Rightarrow5^x=125\)

\(\Rightarrow5^x=5^3\)

\(\Rightarrow x=3\)

5*(5*x+x:5)=52*5

5*5*x+x:5*5=260

25*x+x=260

26*x=260

x=260*26

x=10

bạn chỉ mình phép trên được không, phép dưới mình viết sai

5x+x:5=52

=>5.5.x+x:5.5=260

=25x+x=260

26x=260

=>x=10

\(3\cdot(-2)^{5x+8}+5^2=1\\\Rightarrow 3\cdot(-2)^{5x+8}+25=1\\\Rightarrow 3\cdot(-2)^{5x+8}=1-25\\\Rightarrow 3\cdot(-2)^{5x+8}=-24\\\Rightarrow (-2)^{5x+8}=-24:3\\\Rightarrow (-2)^{5x+8}=-8\\\Rightarrow (-2)^{5x+8}=(-2)^3\\\Rightarrow 5x+8=3\\\Rightarrow 5x=3-8\\\Rightarrow 5x=-5\\\Rightarrow x=-5:5\\\Rightarrow x=-1\)

\(5x+2x\cdot\left(2^3\cdot5-3^2\cdot4\right)+5^2=4^3\)

\(\Rightarrow5x+2x\cdot\left(8\cdot5-9\cdot4\right)+25=64\)

\(\Rightarrow5x+2x\cdot\left(40-36\right)=64-25\)

\(\Rightarrow5x+2x\cdot4=39\)

\(\Rightarrow5x+8x=39\)

\(\Rightarrow x\cdot\left(5+8\right)=39\)

\(\Rightarrow13x=39\)

\(\Rightarrow x=\dfrac{39}{13}\)

\(\Rightarrow x=3\)

Vậy: ...