56.25 minutes
Explanation: to find how long it takes to run one mile, divide 50 minutes by 8 miles.
50/8 = 6.25
Then you can multiply 6.25 by 9 to find the answer.
9 x 6.25 = 56.25 minutes
Every 30 min the tank fills up to 40 gallons
Answer:

Step-by-step explanation:
Let the numbers be x , y
Sum of two numers = -7
x + y = -7------------(I)
Two times the first number equals 4 the second number.
2x = 4y ----------(II)
Divide both sides by 2

x = 2y
Subtitute x = 2y in equation (I)
2y + y = -7
3y = -7
y = -7/3
Plugin y = -7/3 in equation (II)

Answer:
x = 90
Step-by-step explanation:
The 90-degree angle and "x" form a straight line. The degree measurement of a straight line is 180. That means that if one adds 90 and "x", they will get 180, and therefore, x equals 90.