The intersection point of the two lines is (2,1,0).
The respective direction vectors are
L1: <1,2,4>
L2: <4,1,15>
Since the normal vector of the required plane is perpendicular to both direction vectors, the normal vector of the plane is obtained by the cross product of L1 and L2.
i j k
1 2 4
4 1 15
=<30-4, 16-15, 1-8>
=<26, 1, -7>
We know that the plane must pass through (2,1,0), the equation of the plane is
26(x-2)+1(y-1)-7(z-0)=0
simplifying,
26x+y-7z=52+1+0=53
or
26x+y-7z=53
Check:
Put points on L1 in the plane
26(t+2)+(2t+1)-7(4t+0)=53 ok
For L2,
26(4t+2)+(t+1)-7(15t+0)=53 ok
Answer:
His rate is 12 1/2 pages per hour.
Step-by-step explanation:
Given that,
Gordon types 43 3/4 pages in 3 1/2 hours or Gordon types 175/4 pages in 7/2 hours./ We need to find its rate in pages per hour. So,

Hence, his rate is 12 1/2 pages per hour.
They could have assembled total 336 different possible crews.
<em><u>Explanation</u></em>
Total number of trained pilots is 9 and geologists is 4.
The crew should be consisted of 2 pilots and 1 geologist. That means, <u>2 pilots are chosen from total 9 and 1 geologist is chosen from total 4</u>.
Number of ways for choosing 2 pilots from 9
and
Number of ways for choosing 1 geologist from 4 
So, the total possible number of different crews they could have assembled 
If an equation is in absolute value symbols, the answer is always positive. So this equation has no real solution.