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:
Answer:
x = 91.5
Step-by-step explanation:
for 30.5 miles travelled gas used is 1 gallon ← unit rate
To calculate distance travelled multiply gas used by 30.5
For 3 gallons used
distance travelled = 3 × 30.5 = 91.5 miles
⇒ x = 91.5
If you examine the numbers in the question above very well, you will discover that thy have a distinctive pattern. The pattern is this, you add 3 to the first number and then you multiply the next by 2. Lets go over the numbers now:
6 + 3 = 9
9 * 2 = 18
18 + 3 = 21
21 * 2 = 42
42 + 3 = 45
45 * 2 = 90
90 + 3 = 93
93 * 2 = 186, etc.
Thus, the next number after 45 is 90.
The question is to find to rule
9 +9 =18
18+9=27
27+9=36
36+9=45