Mudrik installed a device on his car that guaranteed to increase his gas mileage by 10%. The gas mileage increased 3 miles per gallon after installing the device. How many miles per gallon did he get before the device was installed?

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth