Can you plz help?

Question

Without building the graph, find the coordinates of the point of intersection of the lines given by the equations y=2x+3 and 3x+y=8.

Answer 1

Using the Elimination Method:

    2x  - y = -3             [this is y=2x+3 in Standard Format]

    3x + y =  8

--------------------             [add equations]

    5x       = 5

     x        = 1             [eq1]

 

   3x +  y =  8

   3x        =  3           [multiply eq1 by 3

-------------------          [subtract equations]

           y =  5

 

The point that is on both lines is (1,5).

Answer 2

y=2x+3

3x+y=8

3x+(2x+3)=8

3x+2x+3=8

5x+3=8

5x=8-3

5x=5

x=5/5

x=1

y=2(1)+3

y=2+3

y=5

(x,y)=(1,5)