40/3. You mutiply top and bottom straight across, then simplify.
Answer:

Step-by-step explanation:
As the triangles are similar :
45/55 = (12x - 3)/143
9/11 = (12x - 3)/143
9 x 13 = 12x - 3
12x = 117 + 3
12x = 120
x = 10
Answer: Choice B and D are both correct.
Step-by-step explanation:
The expression has two adjacent negative signs in the middle. The two negative signs are to be multiplied, which then produces one positive sign.
Choice B is therefore correct because the expression becomes 6+6 which is 6 to the right of the number line where the numbers are increasing.
Choice D is also equally correct because the addition of 6 to 6 equals 12(6+6 = 12).