6(x+7)-20=6x
Distribute the 6
x(6)+7(6)-20=6x
Simplify.
6x+42-20=6x
Combine like terms.
6x+22=6x
This has no solution because any number can't equal itself but with 22 more.For example, 5 can't equal 5 plus another 3, or else you would get 5=8 which isn't true.
