Question

9x-2x-28=21

Answer 1

take x common from 1st two terms
\[x(9-2)-28=21\]
then take -28 to right jand side as +28
\[7x=21+28\]

Answer 2

take -28 to the right
9x-2x=21+28
subtract the terms with same variable and add 21to 28
7x=49
we divide by 7
x=7

Answer 3

then add the two numbers
\[7x=49\]
then take the 7 which is in RHS in multiplication to LHS in division
\[x=\frac{ 49 }{ 7 } =7\]

Answer 4

combine like terms then add. :) Goodluck! :D