Is it just me or is it impossible to find x? Someone help

Question 10jur's car can travel 340 miles on 12 gallons. jack's car can travel 390 miles on16 gallons. which person has the best mileage (miles per gallon) and what istheir mileage?

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?

(mc 02.03) what set of reflections and rotations would carry rectangle abcd onto itself? reflect over the y-axis, reflect over the x-axis, rotate 180° rotate 180°, reflect over the x-axis, reflect over the line y=x reflect over the x-axis, rotate 180°, reflect over the x-axis rotate 180, reflect over the y-axis, reflect over the line y=x