The values are always interpreted as (x1, y1) and (x2, y2) in order from left to right, so in this case, (7,2) are (x1, y1) and (15, 8) are (x2, y2)
Let's do this step by step:
Subtract both sides by 7
-2|x-4|= -10
Divide each side by -2
|x-4|= 5
Now since this is an absolute value equation, you will have two answers. This means you make the equation both positive and negative.
X-4= 5and -(x-4)= 5
Solve for x for both
X-4= 5: add four on both sides
X= 9
-x+ 4= 5: subtract 4 and divide by -1
X= -1
So your answer is: X= -1 , 9
Total distance is 132 miles x 2 times/day x 5 days = 1320 miles
That used 4 gallons of fuel, so 1320 miles/4 gallons = 330 miles per gallon
