1) in one minute for first wiil be 1/20
the other 1/30, it means that A paint in one minute 1/20 and B 1/30 then A+B in one minute 1/20 + 1/30 = 3+2/60 = 5 / 60, 5/60 = 1/12
if in one min they make 1/12 then in 12 min they paint all the wall
X² + 4x + 4
x 2
x 2
(x + 2) (x + 2)
x + 2 should be your answer
binomial is having 2 terms
hope this helps
