Question

Select ALL the correct anwsers.

Select all the equations with a solution of x = 3

A) 1/2x - 4 = 2

B) 0.4x - 0.8(x - 4) = 1.3x - 1.9

C) 1/4x + 7 = 31/4

D) x - 2(x + 4) = x + 2

E) 3(x + 4) - x = 18

Answer 1

The answer is B,C,and E

THIS IS RIGHT!!!

Answer 2

Equation B, C and E have solution x = 3.

Explanation:

We are given the following equations in the question:

1)

`\displaystyle(1)/(2)x - 4 = 2\\\\\Rightarrow (1)/(2)x = 6\\\\\Rightarrow x = 12`

2)

`0.4x - 0.8(x - 4) = 1.3x - 1.9\\\Rightarrow 0.4x-0.8x+3.2 = 1.3 x -1.9\\\Rightarrow -0.4x + 3.2 = 1.3x - 1.9\\\Rightarrow1.7x = 5.1\\\Rightarrow x = 3`

3)

`\displaystyle(1)/(4)x + 7 = (31)/(4)\\\\\Rightarrow (1)/(4)x  = (31-28)/(4) = (3)/(4)\\\\\Rightarrow x =3`

4)

`x - 2(x + 4) = x + 2\\\Rightarrow x - 2x-8=x+2\\\Rightarrow -x-8=x+2\\\Rightarrow 2x = -10\\\Rightarrow x = -5`

5)

`3(x + 4) - x = 18\\\Rightarrow 3x +12-x = 18\\\Rightarrow 3x-x = 6\\\\\Rightarrow x = \displaystyle(6)/(2) = 3`

Equation B, C and E have solution x = 3.