Chapter SLE, Section SSLE - Question C30 (pg.14)

C30† Find all solutions to the linear system:

x + y = 5
2x − y = 3

To solve this system of equations, we will first multiply equation 1 by -2 and add to equation 2:

x + y = 5
- 3y = -7

Now we can divide equation 2 by -3 to solve for y:

x + y = 5 y = 7/3

Lastly, we will plug our value for y into equation 1 to solve for x:

x + (7/3) = 15/3 x = 8/3

Our final solution is: x = 8/3, y = 7/3