@phi @mathmale @welshfella Question in comments:)
...??
A rectangle has a length of \[\sqrt[5]{16} =\]Heighth and a width of \[2_{5}^{1}\] Find the area of the rectangle.
The first exponent is length not height :/
is that \[2\frac{ 1 }{ 5 } or 2^{\frac{ 1 }{ 5}}\]
how can you write "5th root" using exponents?
\[2^{\frac{ 1 }{5 }}\]
OK - makes sense - so how can you write "5th root" using exponents?
\[16^{5}?\]
it's \[16^{\frac{ 1 }{ 5 }}\] so write the expression for the area, using the lenght and width in exponent form
\[16^{\frac{ 1 }{5? }} + 2 ^{\frac{ 1 }{ 5 }} ?\]
That doesn't seem right..:/
well area = width TIMES length you have written PLUS so now look and see that \[a^{x} \times b ^{x} = (ab)^{x}\] So simplify your expression like that
Would it be \[2^{\frac{ 4 }{ 5 }}\]
Because the square root of 16 is 4. There was 5 as an exponent so... \[\frac{ 4 }{ 5 } \times \frac{ 1 }{ 5 } = 2 \frac{ 4 }{ 5 }\]
your answer should have been \[16^{\frac{ 1 }{ 5 }}\times 2^{\frac{ 1 }{ 5 }}\] So simplify that using the method I gave above
Oh ok:)
Wait I'm really confused now.
don't panic slow down and go back and read what we said then use my example to simplify your equation
Let's review: We know that length = 5th root (16) And the is the same as \[16^{\frac{ 1 }{ 5 }}\] And we know tha the width is \[2^{\frac{ 1 }{ 5}}\] And we know area= lenght xwidth or \[A = 16^{\frac{ 1 }{ 5}} \times 2^{\frac{ 1 }{ 5 }}\] OK?
I am so sorry! My computer died !
so do you see what we did above...?
Yes, so I would multiply them. Would I turn them improper then?
@MrNood
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a=3440 ?
Well seeing that my answer choices only start with two I suggest your wrong, but thans for the other 3338. Maybe you could turn that into people helping me?
the trick in this one is knowing 16 is 2^4 so do \[ (2^4)^\frac{1}{5} \cdot 2^\frac{1}{5} \]
now you use rules about exponents (2^4)^(1/5) can be written as 2^(4/5) (by multiplying 4*1/5 to get a "new" exponent)
Do I need to turn them improper?
no. once you have the same base (2 in this case) you add the exponents (when multiplying) easy example: \( 2^1 \cdot 2^2 = 2^3 \) in this problem: \(2^\frac{4}{5} \cdot 2^\frac{1}{5} = \)?
you can add the exponents, so add 4/5 plus 1/5 the fractions have the same denominator so you add the tops (numerators) and keep the denominator as 5
lost ?
Would it be 2 square?
do you know how to add 4/5 + 1/5 ?
it would be cheating (a bit) but, you could use a calculator to add 4/5 + 1/5 what do you get ?
4/5 + 1/5 = 1 I know that. Its just all of my answer choices start with 2.
yes, so what we are doing is width times height: \[ \sqrt[5]{16} \cdot 2^\frac{1}{5} \] we changed the "root" to the equivalent "exponent" form: \[ \sqrt[5]{16} = 16^\frac{1}{5} \] \[ 16^\frac{1}{5} \cdot 2^\frac{1}{5} \] we then changed 16 to \(2^4\) (2*2*2*2 is 16) \[ (2^4)^\frac{1}{5} \cdot 2^\frac{1}{5} \] we then use the rule to simplify the first part: \[ 2^\frac{4}{5} \cdot 2^\frac{1}{5} \] now we know if we multiply the same base (2 here) we add the exponents \[ 2^\frac{4}{5} \cdot 2^\frac{1}{5} =2^1\]
And 2 ^1 is the answer. ?
yes, but because 2^1 is 2 we write it simply as 2
Ok thanks! I have a few more can u help[?
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