Respuesta :
Well yea doubling is like getting the same number like 7×3 with equals 21
So you have to find the same number 21, but in a different way like this
7
7 7
+7 ×3
------ -----
21 21
So you have to find the same number 21, but in a different way like this
7
7 7
+7 ×3
------ -----
21 21