60x+80=100x combine like terms
80=100x-60x or 40x divide to get x by itself
80/40=40x/40
20=x
after 20 hrs
Judging on the question I figured that the perpendicular line's slope would be -x since the slope of a perpendicular line is opposite to that of a the reference line.
Thus, your answer should be y=-x+4 considering that is the only equation with the slope of -x.
This is the concept of application of trigonometry;
The height of the tree will be given by:
tan theta=opposite/adjacent
theta=65
opposite=h
adjacent= 10
thus;
tan 65=h/10
h=10 tan 65
h=21.45 m
The distance between the dog and the man is x;
the distance of the man to the tree is (x+10) m
this will be given by:
tan 50= 21.45/(10+x)
getting the reciprocal of the expression we get;
1/tan 50=(10+x)/21.45
cross multiplying the above expression we get;
21.45=(10+x)tan 50
21.45=(10+x)1.2
21.45=12+1.2x
1.2x=21.45-12
1.2x=9.45
x=9.45/1.2
x=7.875
We conclude that the distance of the Firefighter and the dog is x=7.875 m
3/4 x 1/3 = 3/12 which simplified, equals, 1/4
hope this helps
