I think so:
Your working out is probably just the same as my working out!
<span>The object's speed is 8/5 miles per hour or 1.6 mph.</span>
The first equation has no solution
The picture shows all the work I did, the reason I took a pic is because it is a little hard to explain by text, but I hope this helped you!
Answer:
The equations should have been added up to equal 180 instead of being set to equal each other. The two are supplementary angles, which can be seen due the rule that a pair of interior angles on the same side of the transversal is supplementary. To fix this issue from the work that they did, they should subtract the 140 from 180, so the correct measure of DKH is actually 40 degrees.
Step-by-step explanation: