231 - (x - 6) = 1339/13

231 - x + 6 = 103

(231 + 6) - x = 103

237 - x = 103

x = 237 - 103

x = 134

2.x-138=2^3.3^2

2.x-138=8.9

2.x-138=72

2.x=72+138

2.x=210

x=210:2

x=105

vậy x=105

b)231-(x-6)=1339:13

231-(x-6)=103

x-6=231-103

x-6=128

x=128+6

x=134

vậy x=134

nhớ **** cho mình nha

`x:3/6=5/6`

`x=5/6xx3/6`

`x=15/36`

a)  x : 3/6 = 5/6  

     x = 5/6 x 3/6

     x= 15/36

x= \(\dfrac{5}{6}\)x\(\dfrac{3}{6}\)

x= \(\dfrac{15}{36}\)

x=\(\dfrac{5}{12}\)

\(-231-\left(x-6\right)=1339:13\)

\(-231-\left(x-6\right)=103\)

\(x-6=-231-103\)

\(x-6=-334\)

\(x=-334+6\)

\(x=-328\)

\(-231-\left(x-6\right)=-1339:13\)

\(-231-\left(x-6\right)=-103\)

\(x-6=-231+103\)

\(x-6=-128\)

\(x=-128+6\)

\(x=-122\)

B=\(1+3^2+3^4+...+3^{100}\)

9B=\(3^2+3^4+...+3^{100}\)

9B-B=\(\left(3^2+3^4+...+3^{102}\right)-\left(1+3^2+3^4+...+3^{100}\right)\)

8B=\(3^{102}-1\)

B=\(\left(3^{102}-1\right):8\)

C=\(1+5^3+5^6+...+5^{99}\)

125C=\(5^3+5^6+5^9+...+5^{102}\)

125C-C=\(\left(5^3+5^6+5^9+...+5^{102}\right)-\left(1+5^3+5^6+...+5^{99}\right)\)

124C=\(5^{102}-1\)

C=\(\left(5^{102}-1\right):124\)