Question

Find two numbers whose sum is 9 and whose difference is -1

Answer 1

4 and 5 because four plus five is nine and five minus four is one

Answer 2

Answer:

4 and 5

Step-by-step explanation:

Make a system of equations:

x+y=9

x-y=-1

x=9-y

9-y-y=-1

9-2y=-1

-2y=-10

y=5

Since y=5, x must be 4 since 4+5=9 and 4-5=-1

Hope this helped!