(x+5y=8 ) & (-x+2y=-1) determine point of interaction

Question

Determining the point of interaction?? 

Answer 1

The two equations are ideally matched for solution by elimination.  Add the first equation to the second

 

x + 5y - x + 2y = 8 - 1

7y = 7

y = 1

 

substitute this value into the first equation

x + 5(1) = 8

x = 8 - 5 = 3

 

so, the point (3,1) should be the intersection.  

 

Check your our work by substituting these values into the second equation

-(3) + 2(1) = -1

-3 + 2 = -1   Which checks out.