Question

x+7=21

Answer 1

14.

Answer 2

Subtract 7 on both sides.
x+7-7=21-7
x=14.

Answer 3

\[\Huge \color\red {x = 14}\]

Answer 4

see here:
\[x+7=21\]
transpose 7 to right hand side
\[x=21-7\]
\[x=14\]
or
\[x+7=21\]
subtract both sides by 7
\[x+7-7=21-7\]
\[x=14\]
it is ur choice to chose the method , answers are same in both processes