The value of n is 11.
<u>Step-by-step explanation</u>:
The given expression is (n-9) ÷ 10 = -2
<u>To find the value of n</u> :
- From the expression, it is determined that (n-9) is the numerator and 10 is the denominator.
- Cross multiply the denominator in the left side of the expression to the another side.
The expression becomes (n-9) = (10
-2).
⇒ n-9 = -20
Keep the n term on one side and the constants on other side.
⇒ n = -20+9
⇒ n = -11
Therefore, the value of n is 11.
The amount of the tip is 12%
EXPLANATION:
-To formulate an equation, you must first know what data the exercise gives us to locate them correctly.
data:
-6 that must be added to a number.
-four times a number that is equal to 4x
-a result that is equal to 50
Now with these data we formulate the equation:

if we solve the equation we have:
Attached the solution and work.