Assume that the number is x
The opposite of 3 is -3
Since the sum of the number and the opposite of 3 equals 4
Therefore:
[tex]x+(-3)=4[/tex]Remember (+)(-) = (-), so
[tex]x-3=4[/tex]To find x we need to move 3 to the other side by adding 3 to both sides
[tex]\begin{gathered} x-3+3=4+3 \\ x=7 \end{gathered}[/tex]Since x represents the number, so
The number is 7
Let us check the answer
7 + -3 = 4
The answer is correct