Answer: the third one
Step-by-step explanation:
There are going to be two solutions because the "biggest" x is x^2 but you can factor to find what they actually are.
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
The 5x and the combination of (40° + x) are "vertical angles".
Vertical angles are equal.
So
5x = 40° + x
Subtract 'x' from each side: 4x = 40°
Divide each side by 4 : x = ?
is this the full question?