Step-by-step explanation:
The given statement can be expressed as:

Hello,
1 meter is equal to 10 decimeters.
SO, if we convert 40 meters to decimeters, we multiply 40 meters by 10 decimeters, getting 400 decimeters.
Hope this helps!
May
y = -9
Ok so to write the equation of the line you will need the slope and y-intercept. Since we are given two-point we can easily find the slope by using this equation for slope formula:

So now that we have our equation we can just plug in the numbers:

After subtracting you should get:
0/8
Since zero is in the numerator and you can't divide zero by anything, the slope is 0. We still need the y-intercept for the equation however since the slope is 0 there is no need to put anything else.
Then to find the y-intercept all you have to do is plug in one of the coordinatines into the slope equation to solve, for example, using the point (5,-9):

B is the variable for the y-intercept. Also notice how I put 0 as our slope into the equation. Now all you have to do is solve for b. Which you would get b = -9. Since you have your slope and your y-intercept now you just write out your equatoin for the line which is:
y = 0x - 9
**Just write it as
y = -9