Answer
$x+(-4)=18$ OR $x-4=18$
$x = 22$
Work Step by Step
We will use x as the unknown number. First we must write an equation representing the verbal sentence.
To write "the sum of a number and -4 is 18" as an equation, we need to add -4 to the number, x, and set it equal to 18. Therefore, the equation is: $x+(-4)=18$. When we add a negative, it is the same as subtraction. Therefore, the equation can be written as: $x-4=18$
To solve, we need to add 4 to both sides:
$x-4 +4=18+4$
resulting in the answer: $x = 22$.
