So if you want it to be 9 less than your number (x) then you would subtract nine.
So it would be:
x - 9.
So if your "number" is 12 then you would substitute x for 12 and it would be 12-9. The answer is 3. So 3 is 9 less than a number (12).
I believe
For this case we have that by definition, the equation of a line in the slope-intercept form is given by:

Where:
m: Is the slope
b: Is the cut-off point with the y axis
We have the following equation:

We manipulate algebraically:
We subtract 10 from both sides of the equation:

We subtract 3x from both sides of the equation:

We multiply by -1 on both sides of the equation:

We divide between 5 on both sides of the equation:

Thus, the equation in the slope-intercept form is 
Answer:

Answer:
x = -16
Step-by-step explanation:
-4x - 13 = 51
-4x = 51 + 13
-4x = 64
x = -16
7/8 = x/48
Perform cross multiplication:
a/b = c/d
ad = bc
a = 7 ; b = 8 ; c = x ; d = 48
7*48 = 8x
336 = 8x
336/8 = x
42 = x
7/8 = 42/48
42 ÷ 6 = 7
48 ÷ 6 = 8