Answer:
Line AB is Perpendicular to line CD
Line AB Parallel to line EF
so 5 people work each one for 21 minutes, that means 21+21+21+21+21 minutes altogether, namely 105 minutes, it took that long for 7 walls, hmmmm how long for just one wall then? well, 105 ÷ 7, namely 15 minutes then, for just 1 wall.
now, if it takes 15 minutes of work to do one wall, what about 5 walls? well, that'd be 15*5 or 75 minutes.
so if we have 3 folks working, how much would each one work? well, 75 ÷ 3, namely 25 minutes, so each of them will work 25 minutes, namely 25+25+25 minutes, so in 25 minutes, they'll be done with 5 walls.
Answer:

Step-by-step explanation:
-p(d+z)=-2z+59
-pd-pz=-2z+59
lets bring all z integers on one side
-2z+pz = -pd-59
z(-2+p)=-pd-59
z = (pd-59) / (-2+p)
Answer:
OPtion B
Step by step explanation:
Lets plug in a random value for x.
Lets say 5 is x
-8(-5-5)=(y+1)^2
5-5 = 0
-8(0) = 0
0 = (y+1)^2
Square root of both sides
0 = y+1
subtract one from both sides
-1 = y
that means the x is 5 and the y is -1. Option B illustrates exactly that!