hiya!
1) Expand to get 20x + 40 = 85 + 5x
Take 5x from both sides, gives 15x + 40 = 85
Take 40 from both sides, gives 15x = 45
Divide both sides by 15, gives x = 3
2) Group like terms to get 6x + 3(x + 1) = 30
Expand the brackets, gives 6x + 3x + 3 = 30
Group again gives 9x + 3 = 30
Take 3 from both sides, gives 9x = 27
Divide by 9 on both sides, gives x = 3
3) Is there supposed to be an x-term in this one?