Solve the system of equations by graphing

Question

x=-y

x+y=9

 

Use the graphing tool to graph the system.

 

What is the solution of the system of equations? Select the correct choice below and, if necessary, fill in the box to complete your choice.

 

A. __(Type an ordered pair)

B. The system of equations has infinitely many solutions.

C. The system of equations has no solution

Answer 1

C. the system has no solution

graph the two equations and they are parallel lines that never intersect. they have no real or complex solution.

x=-y add y to both sides

x+ y = 0

the 2nd equation contradicts the above

x+ y = 9

the sum can't be both 0 and 9, no values of x and y would make that true.

(You might say there are 2 surreal solutions though. "Surreal numbers include infinity and negative infinity. If x=infinity and y = -infinity, or if x=-infinity and y=+ infinity, then x+y = any finite number, including 0 or 9. "surreal" numbers are not real or imaginary)