what does the x mean in the equation for 5+2(x-1)=12

Question

 I'm so confused on the lesson I am doing.

 

Answer 1

In this equation, x stands for a number.

 

When we solve the equation, we will know what that number is.

 

So, 5 + 2(x - 1) = 12

Expanding, we get 5 + 2x - 2 = 12

Combining, we get 2x = 12 - 5 + 2, which becomes 2x = 9

We divide both sides of the equation by 2

So, x = 4.5