The length of a line is x metres. Write down an expression, in terms of x, for the length of the line in millimetres.

50-38=12

step-by-step explanation:

i think asking google will you get the answer to that question

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.