Answer:
9 - 7x - x²
Step-by-step explanation:
-4x+2x2-x²+5-3x = -4x-3x+2x2+5-x²
I arranged the like terms together so it is easier to do the calculations.
-4x-3x+2x2+5-x² = -7x+4+5-x²
Simplify.
-7x+4+5-x² = 9-7x-x²
There u go tried my best to work it out!! :))
First of all, you would use the FOIL method for -5(a + 3). This means to just multiply -5 to all of the values in the parenthesis. This would equal:
-5a -15 = -55
Then after, you would add 15 for both sides and get -5a = -40
Divide by -5 on both sides, you get a = 8.
Here is a visual representation: https://puu.sh/zPxLC/a16740d0ce.png
Phone card = $20
You need to minus 17.92 from 20 = $2.08
$2.08 / 0.13 = how many minutes
= 16
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
