SOLUTION: Can someone please help me???!!? -14x = -632 - 26y y = (7/13)x - 316/13 A Parallel BPerpendicular CNot Parallel and Not Perpendicular DVertical E Horizontal

Algebra ->  College  -> Linear Algebra -> SOLUTION: Can someone please help me???!!? -14x = -632 - 26y y = (7/13)x - 316/13 A Parallel BPerpendicular CNot Parallel and Not Perpendicular DVertical E Horizontal       Log On


   

Question 768533: Can someone please help me???!!?
-14x = -632 - 26y
y = (7/13)x - 316/13
A Parallel
BPerpendicular
CNot Parallel and Not Perpendicular
DVertical
E Horizontal
Mark leaves home and drives at a constant speed, on his way to the beach. He stops to have lunch. Two hours after leaving the restaurant, he has traveled 110 miles. Four hours after leaving the restaurant, he has traveled 210 miles. How far from home was Mark when he stopped for lunch?
A 55 miles
B40 miles
C20 miles
D10 miles
E 50 miles
F 20 miles

ps: I think its 55, right? im not so sure
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!


Prob 1:

-14x = -632 - 26y 

y = (7/13)x - 316/13 



1st eqn can be rewritten as:

26%2Ay+=+14%2Ax+-+632 Dividing both sides, by 26

y+=+%2814%2F26%29%2Ax+-+632%2F26 Simplifying

y+=+%287%2F13%29%2Ax+-+316%2F13

This is the same as the second line! So the two equations refer to the same

line - None of the choices are correct.



Prob 2:

Consider the period between 2 hours and 4 hours. At the end of 2 hours, he was 110

miles away, and at the end of 4 hours, he was 210 miles away. So in 2 hours,

he has travelled (210-110) = 100 miles.

So the average speed = 100/2 = 50.



That means, in the 2 hours after leaving the restaurant, he would have travelled

(50*2) = 100 miles as well. But it is stated that he has travelled a TOTAL 

distance of 110 miles at that time. So, the distance from his home to the 

restaurant is (110 - 100) = 10 miles. Ans D.



Hope you got it :)