Considering that you are planning the trip with limited budget and only for 4 days (=96h) you must value both time and money when doing it.
If you use the bus you spend $75 + $75=$150 and 12h + 12h = 24h. This means you spend $150 to enjoy 96h - 24h = 72h of actually camping. This means you pay $150/72h = $2,08 per hour of actual camping.
On the other hand if you choose the plane you spend $150 + $ 150 = $300 and 1,5h + 1,5h = 3h. This means you spend $300 to enjoy 96h - 3h = 93h. This means you pay $300/93h = $3,22 per hour of actual camping.
Considering all that, taking the bus his the most cost-effective option (and the cheaper one also).
Set up two fractions:
8/x and 3/5
Set them equal to each other and cross multiply to get:
8*5 = 3x
40 = 3x
13.3 = x or 13 and 1/3 feet tall.
The slope is 0 the equation of the line is y=3
You can calculate it using the law of cosines: c^2=a^2+b^2-2*a*b*cos(C)
your triangle is
CD=15=a
CE=?=b
DE=CE+3=b+3=c
and C=90°
-> insert those values, with c substituted with b+3 to remove c
c^2=a^2+b^2-2*a*b*cos(C)
(b+3)^2=15^2+b^2-2*15*b*cos(90)
cos(90)=0->
(b+3)^2=15^2+b^2
b^2+2*3*b+3^2=225+b^2
6b+9=225
6b=216
b=36=CE
DE=CE+3=36+3=39