Answer
D) $6+2x=72$
Work Step by Step
Let's translate English terms into mathematics terms.
Is in English means equal in math, which results in =72 on one side of the equation. Twice the number, lets say the number we are talking about is x, means it is 2 times the number x; resulting in 2x. Six more means that it is we would add six in the equation on the side of the term 2x. Resulting in equation 72 = 2x +6. We can also rearrange the equation in way that results in 6 + 2x = 72.
In order to solve the equation, you move the like terms on one side and the unlike terms on the other. In this question, you move 6 to the other hand which makes it 72-6 which is 66 and on the left hand, you have 2x. We then take the two which is multiplied by x since it is a like term and move it to the right-hand side to get 66/2 which is 33.
Note: When we move terms to the other side, they change symbols
a (-) sign turns into a (+) sign and a ($\times$) sign changes to a ($\div$) and vice versa.