Question

2(x+1)-10=20 
b , 1/3 . x -1 =2/3 
c , 10/3 : x = 4/5 
d x : -2/3 - 1 = 9

Answer 1

a.

\(\Leftrightarrow2x+2=20+10=30\\ \Leftrightarrow2x=30-2=28\\ \Leftrightarrow x=\dfrac{28}{2}=14\)

b.

\(\Leftrightarrow\dfrac{x}{3}=\dfrac{2}{3}+1=\dfrac{5}{3}\\ \Leftrightarrow x=\dfrac{5}{3}\times3=5\)

c.

\(\Leftrightarrow x=\dfrac{10}{3}:\dfrac{4}{5}=\dfrac{25}{6}\)

d.

\(\Leftrightarrow x:-\dfrac{2}{3}=9+1=10\\ \Leftrightarrow x=10\times-\dfrac{2}{3}=-\dfrac{20}{3}\)

Answer 2

a. 2x + 2 - 10 = 20

2x = 20 + 10 - 2

2x = 28

x = 28 : 2 = 14

b. 1/3x - 1 = 2/3

1/3x = 2/3 + 1

1/3x = 5/3

x = 5/3 : 1/3 = 5/3 x 3/1 = 5

c. 10/3 : x = 4/5

x = 10/3 : 4/5 

x = 10/3 x 5/4 = 25/6

d. x : (-2/3) - 1 = 9

x : (-2/3) = 10

x = 10 : (-2/3)

x = 10 x (-3/2) = -15

Answer 3

a. \(2\left(x+1\right)-10=20\)

\(2\left(x+1\right)=30\\ x+1=15\\ x=14\)

b. \(\dfrac{1}{3}x-1=\dfrac{2}{3}\)

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

c. \(\dfrac{10}{3}:x=\dfrac{4}{5}\)

\(x=\dfrac{10}{3}:\dfrac{4}{5}\\ x=\dfrac{25}{6}\)

d. \(x:-\dfrac{2}{3}-1=9\\ x:-\dfrac{2}{3}=10\\ x=10.-\dfrac{2}{3}\\ x=-\dfrac{20}{3}\)