The expression [tex]$6 \sqrt[5]{3^5 x^{45}} \cdot \sqrt[8]{2^8 x}$[/tex] is equivalent to [tex]$a x^b$[/tex] where [tex][tex]$a$[/tex][/tex] and [tex]$b$[/tex] are positive constants and [tex]$x \ \textgreater \ 1[/tex]. What is the value of [tex]$a + b$[/tex]?



Answer :

To solve the expression [tex]\(6 \sqrt[5]{3^5 x^{45}} \cdot \sqrt[8]{2^8 x}\)[/tex] and express it in the form [tex]\(a x^b\)[/tex], we can proceed with detailed steps as follows:

1. Simplifying each term inside the expression:
- The first part of the expression is [tex]\( \sqrt[5]{3^5 x^{45}} \)[/tex]:
[tex]\[ \sqrt[5]{3^5 x^{45}} = (3^5 \cdot x^{45})^{\frac{1}{5}} = 3^{\frac{5}{5}} \cdot x^{\frac{45}{5}} = 3^1 \cdot x^9 = 3 \cdot x^9 \][/tex]

- The second part of the expression is [tex]\( \sqrt[8]{2^8 x} \)[/tex]:
[tex]\[ \sqrt[8]{2^8 x} = (2^8 \cdot x)^{\frac{1}{8}} = 2^{\frac{8}{8}} \cdot x^{\frac{1}{8}} = 2^1 \cdot x^{\frac{1}{8}} = 2 \cdot x^{\frac{1}{8}} \][/tex]

2. Combine the simplified term components:
- Now, combining these simplified terms with the constant 6 from the original expression, we get:
[tex]\[ 6 \cdot (3 \cdot x^9) \cdot (2 \cdot x^{\frac{1}{8}}) \][/tex]

- First, handle the coefficients (numerical values):
[tex]\[ 6 \cdot 3 \cdot 2 = 36 \][/tex]

- Next, handle the [tex]\(x\)[/tex] terms by combining the exponents:
[tex]\[ x^9 \cdot x^{\frac{1}{8}} = x^{9 + \frac{1}{8}} \][/tex]

- Adding the exponents together:
[tex]\[ 9 + \frac{1}{8} = 9.125 \][/tex]

3. Forming the final expression:
- The combined expression is:
[tex]\[ 36 \cdot x^{9.125} \][/tex]

Which means in the form [tex]\(a x^b\)[/tex], [tex]\(a = 36\)[/tex] and [tex]\(b = 9.125\)[/tex].

4. Calculating [tex]\(a + b\)[/tex]:
[tex]\[ a + b = 36 + 9.125 = 45.125 \][/tex]

Therefore, the value of [tex]\(a + b\)[/tex] is [tex]\(45.125\)[/tex].