To find the distance between two points A and B you can use the formula
[tex]\begin{gathered} d=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)^2} \\ \text{ Where A and B have the coordinates} \\ A(x_1,y_1) \\ B(x_2,y_2) \end{gathered}[/tex]
So, in this case, you have
[tex]\begin{gathered} A(-3,4) \\ B(4,4) \end{gathered}[/tex][tex]\begin{gathered} d=\sqrt[]{(4_{}-(-3))^2+(4-4)^2} \\ d=\sqrt[]{(4_{}+3)^2+(0)^2} \\ d=\sqrt[]{(7)^2} \\ d=7 \end{gathered}[/tex]
Therefore, the distance between these points is 7 units.
Graphically,
