Respuesta :

Let x and y be two numbers.

Given that the sum of the numbers is 18.

[tex]x+y=18[/tex]

Given that the value of x=20.

[tex]\begin{gathered} x+y=18 \\ 20+y=18 \\ y=18-20 \\ y=-2 \end{gathered}[/tex]

Thus, the value of y is -2.