Question 617542
Start with  y=2x + 1
Move the 1   y - 1 = 2x
Divide by two  (y-1)/2 = x or x= 1/2 x (y-1)

2x +3 = x + 8
Take x from each side   x + 3 = 8
Take 3 from each side   x = 5

And 4(x + 2) = 20
Remove bracket 4x + 8 = 20
Take 8 from each side 4x = 12
Divide by four   x = 3