The flight is 5.25 hours long
Hope this helps :)
The orthocenter is the point where the three altitudes meet.
sketch the graph and you will see that AB is a horizontal line, the altitude is a vertical line through the point (1,3), so the equation of this altitude is x=1
next, find another altitude. I'll use the altitude of BC.
the slope of BC is (6-3)/(4-1)=1, so the slope of the altitude, which is perpendicular to BC going through the point A (0,6), is -1, the equation of the altitude of BC is y=-x+6
the system of equation : x=1
y=-x+6
has a solution (1, 5)
the solution is where the two lines meet, the meeting point is the orthocenter.
Double check by find the equation for other altitude:
slope of AC: (3-6)/(1-0)=-3
slope of altitude of AC: 1/3
equation of altitude of AC: y=(1/3)x+b
the altitude of AC goes through point B (4,6), so we can find out b by plug x=4, y=6 in the equation: 6=(1/3)*4+b, b=14/3
y=(1/3)x+14/3
Is (1,5) also a solution to this equation? Plug x=1 in the equation, we get y=5, so yes, (1,5) is a point on the third altitude.
so did you get what I solved the answer is D ok
First we calculate how many ways you can choose four books from a set of eight.
We use the formula n! / [r! * (n-r)!]
8! / [4! * 4!]
= 8*7*6*5 / 4*3*2*1 = 70 ways
Then we have to calculate how many permutations can be made from 4 objects which equals 4*3*2*1 = 24
So, the TOTAL number of ways = 70 * 24 = 1,680
