It takes the son one and half hours to clean the house. To find this you need the equations F+S=2 and F+1=S. (F=father and S=son) You take the F+1 and substitute it in for S in F+S to get F+(F+1)=2. Then you combined like factors, 2F+1=2, and simplify to get F=.5hr. After this you plug .5 in to F+1=S to get (.5)+1=S, meaning it takes the son 1.5 hour to clean the house.
<h3>Answer:</h3>
room 3 or 4
<h3>Explanation:</h3>
We assume the inequalities tell the rooms that were checked and found empty.
The solution to 3) is ...
... 2x + 3 > 11
... 2x > 8 . . . . . subtract 3
... x > 4 . . . . . . .divide by 2
The solution to 4) is ...
... -3x > -9
... x < 3 . . . . . . divide by -3
Thus, rooms greater than 4 and less than 3 were found empty. Rooms 3 and 4 were not checked, so either one could hold Nessie.
_____
The other inequalities have solutions that are already covered by the solutions to these.
1) x < -1 . . . . after subtacting 4
2) x > 5 . . . . after multiplying by 5
f
'
(
x
)
=
1
(
x
+
1
)
2
Explanation:
differentiating from first principles
f
'
(
x
)
=
lim
h
→
0
f
(
x
+
h
)
−
f
(
x
)
h
f
'
(
x
)
=
lim
h
→
0
x
+
h
x
+
h
+
1
−
x
x
+
1
h
the aim now is to eliminate h from the denominator
f
'
(
x
)
=
lim
h
=0
(
x
+
h
)
(
x
+
1
)−
x
(
x
+
h
+
1)
h
(
x
+
1
)
(
x
+
h
+
1
)
f
'
(
x
)
=
lim
h
→
0
x
2
+
h
x
+
x
+
h
−
x
2
−
h
x
−
x
h
(
x
+
1
)
(
x+h
+
1
)
f
'
(
x
)
=
lim
h
→
0
h
1
h
1
(
x
+
1
)
(
x
+
h
+1
)
f
'
(
x
)
=
1
(
x
+
1
)
2
Use Conects it’s a better app for math hope this helps