How can conversion of measurements me solve real world problems

In different parts of the world people use different units. Being able to convert will help me understand and fit into their surroundings. Like for instance in Canada people measure speed in kilometers, so their speed limits are written in kmph. While in America the speed is measured in miles so Mph. Knowinf=g the conversions can help you drive safely and not get a ticket.
Hope that was what you were expecting.

First subtract 10 from both side
y^2+6y-16=0
(y+8)(y-2)=0
-8 and 2