First, expand the terms in parenthesis on both sides of the inequality by multiplying each term within the parenthesis by the term outside the parenthesis:
#color(red)(7)(b - 1) <= color(blue)(2)(2b + 4)#
#(color(red)(7) * b) - (color(red)(7) * 1) <= (color(blue)(2) * 2b) + (color(blue)(2) * 4)#
#7b - 7 <= 4b + 8#
Next, add #color(red)(7)# and subtract #color(blue)(4b)# from each side of the inequality to isolate the #b# term while keeping the inequality balanced:
#-color(blue)(4b) + 7b - 7 + color(red)(7) <= -color(blue)(4b) + 4b + 8 + color(red)(7)#
#(-color(blue)(4) + 7)b - 0 <= 0 + 15#
#3b <= 15#
Now, divide each side of the inequality by #color(red)(3)# to solve for #b# while keeping the inequality balanced:
#(3b)/color(red)(3) <= 15/color(red)(3)#
#(color(red)(cancel(color(black)(3)))b)/cancel(color(red)(3)) <= 5#
#b <= 5#
