what does 2x mean?

Question

im doing brick wall problems and i need help this is my equation

 

x+12+12+2x= 42

i need to work out what x is but im not sure about 2x.

Answer 1

2x refers to "2 times x"... the 2 is the constant coefficient, and you are multiplying that by the term x.  You can combine the x terms above as x + 2x = 3x, because the x term is understood to have a 1 in front of it, even though it is not explicitly shown.

To solve your questions, you simply have to combine like terms and then simplify things.  So, you have:

x + 12 + 12 + 2x = 42

x + 2x + 12 + 12 = 42

3x + 24 = 42

3x = 18

x = 6