what is the solution of the system of equations : x - 2y = 1 and x + y = 4

Answer 1

x - 2y = 1

x + y = 4

Subtract the bottom equation from the top equation and get

-3y = -3

y = 1

Plug this value of y into either equation and solve for x. Using the bottom equation,

x = 4 - y = 4 - 1 = 3

Test the solution.