Is there supposed to be a picture attached?
Answer:
24 hours
Step-by-step explanation:
The computation of the number of hours taken by Bobby to build the robot by himself is shown below:
Given that
Bobby could take 12 hours
Together they could build in 8 hours
So based on the above information
the number of hours taken by Bobby to build the robot by himself is
Let us assume the above line be x
So,

x = 24 hours
Answer:
m=5
Step-by-step explanation:
Y2-Y1
m= ______
X2-X1
X1= 3
Y1= 15
X2= 9
Y2= 45
45-15 30
____= ____
9-3 6
30/6=5
m=5