The sum of two numbers is 0. One of the numbers is nine less than twice the other. Find the numbers
Let
x -----> one number
y ----> the other number
we have that
x+y=0 ------> x=-y -----> equation 1
x=2y-9 ----> equation 2
equate both equations
-y=2y-9
2y+y=9
3y=9
y=3
therefore
the numbers are 3 and -3