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Let p = (a,b) be the point of intersection of the line y = 2x-10 and the line through (7,8) and (9,0) Compute a+b.

 Jul 27, 2021
 #1
avatar+37159 
+1

First, you will have to find the equation of the line between the two given points...  slope, m = rise/run = 8/-2 = -4

line equation is then y = -4x +36

Now equate the two line equations

 

2x-10 = -4x+36      now solve this  for the 'x' coordinate  which is 'a'   

                                   use this value in either of the line equations to calculate the 'y' coordinate....which is 'b' 

 Jul 27, 2021
edited by ElectricPavlov  Jul 27, 2021
 #2
avatar+11 
0

it is still confusing to me

 Jul 27, 2021
 #3
avatar+37159 
0

Probably so....which part?

ElectricPavlov  Jul 27, 2021
 #4
avatar+11 
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the last part of it

 Jul 27, 2021
 #6
avatar+37159 
+1

Once you have the equations for two lines, the point of intersection (a,b) satisfies both equations ....so if you equate the line equations

   you can solve for the point x, which is 'a'

2x-10 = -4x+36  

6x = 46

x = 46/6    = 'a'      now use this value in one of the equations to calculate y (which is the 'b' value) .....then add them together to answer your Q

ElectricPavlov  Jul 27, 2021
 #5
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0

Hello? Mr.Electric Pavlov

 Jul 27, 2021

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