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Let’s check out your problem:
Simplify. Rationalize the denominator.
\newline
8
2
−
5
\frac{8}{2 - \sqrt{5}}
2
−
5
8
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Math Problems
Algebra 2
Simplify radical expressions using conjugates
Full solution
Q.
Simplify. Rationalize the denominator.
\newline
8
2
−
5
\frac{8}{2 - \sqrt{5}}
2
−
5
8
Select conjugate:
Select the conjugate of the denominator
2
−
5
2 - \sqrt{5}
2
−
5
to rationalize it.
\newline
The conjugate of
a
−
b
a - \sqrt{b}
a
−
b
is
a
+
b
a + \sqrt{b}
a
+
b
.
\newline
So, the conjugate of
2
−
5
2 - \sqrt{5}
2
−
5
is
2
+
5
2 + \sqrt{5}
2
+
5
.
Multiply by conjugate:
Multiply the numerator and the denominator by the conjugate of the denominator.
\newline
So, multiply
8
2
−
5
\frac{8}{2 - \sqrt{5}}
2
−
5
8
by
2
+
5
2
+
5
\frac{2 + \sqrt{5}}{2 + \sqrt{5}}
2
+
5
2
+
5
.
Multiply numerator:
Perform the multiplication in the numerator:
8
×
(
2
+
5
)
8 \times (2 + \sqrt{5})
8
×
(
2
+
5
)
. This gives us
16
+
8
×
5
16 + 8 \times \sqrt{5}
16
+
8
×
5
.
Multiply denominator:
Perform the multiplication in the denominator:
(
2
−
5
)
×
(
2
+
5
)
(2 - \sqrt{5}) \times (2 + \sqrt{5})
(
2
−
5
)
×
(
2
+
5
)
. This is a difference of squares, which gives us
2
2
−
(
5
)
2
2^2 - (\sqrt{5})^2
2
2
−
(
5
)
2
.
Simplify denominator:
Simplify the denominator:
2
2
−
(
5
)
2
2^2 - (\sqrt{5})^2
2
2
−
(
5
)
2
. This gives us
4
−
5
4 - 5
4
−
5
.
Calculate denominator:
Calculate the simplified denominator:
4
−
5
4 - 5
4
−
5
. This gives us
−
1
-1
−
1
.
Combine numerator and denominator:
Combine the simplified numerator and denominator:
(
16
+
8
⋅
5
)
/
−
1
(16 + 8 \cdot \sqrt{5}) / -1
(
16
+
8
⋅
5
)
/
−
1
.
Simplify expression:
Simplify the expression by dividing both terms in the numerator by the denominator.
\newline
This gives us
−
16
−
8
×
5
-16 - 8 \times \sqrt{5}
−
16
−
8
×
5
.
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\newline
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\newline
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\newline
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x
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\newline
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\newline
(A)
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7
7
\newline
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3
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3
52
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Question
What is the average value of
1
x
\frac{1}{x}
x
1
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4
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x
≤
8
4 \leq x \leq 8
4
≤
x
≤
8
?
\newline
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1
1
1
answer:
\newline
(A)
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16
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16
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\newline
(B)
1
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4
l
n
(
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\newline
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p
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Question
Simplify the expression. Write your answers using integers or improper fractions.
\newline
−
(
−
2
y
+
8
)
+
1
2
y
-(-2 y+8)+\frac{1}{2} y
−
(
−
2
y
+
8
)
+
2
1
y
\newline
Answer:
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Question
Simplify the expression. Write your answers using integers or improper fractions.
\newline
−
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5
(
−
25
q
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)
−
q
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−
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1
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q
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)
−
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\newline
Answer:
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Area .
\newline
A
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Question
Simplify. Rationalize the denominator.
\newline
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