Question

Marlena solved the equation 2x + 5 = –10 – x. Her steps are shown below.

2x + 5 = –10 – x

3x + 5 = –10
3x = –15
x = –5
Use the drop-down menus to justify Marlena’s work in each step of the process.

Step 1:

Step 2:

Step 3:

Answer 1

Explanation:

Given equation,

`\sf 2x + 5 = -10- x`

Step 1 :

`\sf 2x + 5 = -10 - x`

In the first step, Move - x from the right side to the left side of the equation.

In right hand side the sign on x was negative, but on moving to the left the sign will change to positive.

`\sf 2x + x + 5 = - 10`

(Adding 2x and x)

`\sf 3x + 5 = 10`

Step 2:

Move +5 to the right side of the equation.

The sign on +5 will change to negative.

`\sf 3x = -10 - 5`

(Adding 10 and 5, because, - - = +)

`\sf 3x = -15`

Step 3 :

Divide 3 on both the sides,

`\sf (3x)/(3) = (-15)/(3)`

`\sf x = -5`