Step by step:
6 - 2(x + 6) = 3x + 4
6 - 2x -12 = 3x + 4
6 - 12 = 5x + 4
-6 = 5x + 4
-10 = 5x
-2 = x
So, x = -2
Distance from A to B is 6.7
Hopes that help
Area = length * width
length = (2 * width) - 1

Since length cannot be negative, w = -2 is not a solution. Thus,

is your width.
Since length = 2 * width - 1, plug in width:
The values of 4s that are present in 4400 are 4 thousands and 4 hundreds.
4400 = 4 thousands + 4 hundreds + 0 tens + 0 ones
so the value of first 4 is 4 thousands and second 4 is 4 hundreds.