One car 40 miles /gallon
other car 30 miles/gallon
..
Total miles = 165
gas used = 45 gallons
...
let first car drive x miles
second car drive y miles
..
x/40 + y/30 = 45
(30x+40y)/30*40 = 45
30x+40y = 45*40*30
30x+40y=54,000
Answer:b
Step-by-step explanation:I took it
The first tank contains
486 gal - (4 gal/week) <em>t</em>
gal of water after <em>t</em> weeks.
Similarly, the second tank contains
648 gal - (7 gal/week) <em>t</em>
gal of water.
The tanks hold the same amount of water when these two amounts are equal:
486 gal - (4 gal/week) <em>t</em> = 648 gal - (7 gal/week) <em>t</em>
(7 gal/week) <em>t</em> - (4 gal/week) <em>t</em> = 648 gal - 486 gal
(3 gal/week) <em>t</em> = 162 gal
<em>t</em> = (162 gal) / (3 gal/week)
<em>t</em> = 54 weeks
90 squareroot 2
In decimal form it’s 127.27922
-7-13k would be the answer
