Answer: its x = 3
Step-by-step explanation:
The maximum or minimum of a quadratic function occurs at
x
=
−
b
2
a
. If
a
is negative, the maximum value of the function is
f
(
−
b
2
a
)
. If
a
is positive, the minimum value of the function is
f
(
−
b
2
a
)
.
f
min
x
=
a
x
2
+
b
x
+
c
occurs at
x
=
−
b
2
a
Find the value of
x
equal to
−
b
2
a
.
x
=
−
b
2
a
Substitute in the values of
a
and
b
.
x
=
−
−
12
2
(
2
)
Remove parentheses.
x
=
−
−
12
2
(
2
)
Simplify
−
−
12
2
(
2
)
.
Tap for more steps...
x
=
3
The maximum or minimum of a quadratic function occurs at
x
=
−
b
2
a
. If
a
is negative, the maximum value of the function is
f
(
−
b
2
a
)
. If
a
is positive, the minimum value of the function is
f
(
−
b
2
a
)
.
f
min
x
=
a
x
2
+
b
x
+
c
occurs at
x
=
−
b
2
a
Find the value of
x
equal to
−
b
2
a
.
x
=
−
b
2
a
Substitute in the values of
a
and
b
.
x
=
−
−
12
2
(
2
)
Remove parentheses.
x
=
−
−
12
2
(
2
)
Simplify
−
−
12
2
(
2
)
.
Tap for more steps...
x
=
3
Complete question :
Mr. Nelson lost one of his students' test papers. He knows that the other 4 students scored as follows: 60, 62, 56, 57. He also knows that the average score is 59.2. What is the score on the missing paper?
Answer:
61
Step-by-step explanation:
Given the following :
Total number of students = 4 + 1 missing = 5
Score on the four avaliable papers = 60, 62, 56, 57
Average score of the 5 papers = 59.2
Score on missing paper :
Sum of each score / number of papers
Sum of each score = sum of available scores + missing score
Let missing score = m
(60 + 62 + 56 + 57 + m) = 235 + m
Recall:
Average = total sum / number of observations
Hence,
59.2 = (235 + m) / 5
59.2 × 5 = 235 + m
296 = 235 + m
m = 296 - 235
m = 61
Missing score = 61
Answer:
-8 ≤ y ≤ 8
Step-by-step explanation:
Subtract 7 from the first one:
y ≥ -8
Subtract 3 from the second one, then multiply by 4.
y/4 ≤ 2
y ≤ 8
Now, you can write these as a compound inequality:
-8 ≤ y ≤ 8
_____
<em>Additional comment</em>
You basically solve these the same way you would an equation. The only difference is that multiplying or dividing by a negative number will reverse the inequality symbol:
2 > 1
-2 < -1 . . . . . multiplied above by -1.
