You add 70 + 50 then you multiply it by 7.5 and you get, 900 gallons.
That's <u>always</u> true if <em>either</em> the exponent <em>or </em>the base is less than ' 1 '.
(But not always of they both are.)
The park is a total of 3+3 = 6 miles east of the mall, and 4+5=9 miles north of it. The Pythagorean theorem tells you the straight-line distance in miles is
√(6² +9²) = √117 ≈ 10.8