600 seconds would be 10 minutes, as there are 60 seconds in a minute.
Expressed as hours, that would be 1/6 of an hour.
The measures of the two angles are 82.1 and 7.9.
1/12 of the road left to build
Solve by substitution


Just plug in y=-x-1 into y+x=3
So we get:

Simplify that:

And since that is not true, that means this system of equations has no solutions!