10. If [tex]x=2[/tex] and [tex]y=4[/tex], then

[tex]\[
\left(\frac{x}{y}\right)^{x-y} + \left(\frac{y}{x}\right)^{y-x} =
\][/tex]

(a) 4

(b) 8

(c) 12



Answer :

Sure, let's solve the problem step-by-step with the given values [tex]\(x = 2\)[/tex] and [tex]\(y = 4\)[/tex].

1. First, substitute [tex]\(x\)[/tex] and [tex]\(y\)[/tex] into the first term [tex]\(\left(\frac{x}{y}\right)^{x-y}\)[/tex]:

[tex]\[ \left(\frac{x}{y}\right)^{x-y} = \left(\frac{2}{4}\right)^{2-4} \][/tex]

2. Calculate the fraction inside the parentheses:

[tex]\[ \frac{2}{4} = \frac{1}{2} \][/tex]

3. Now calculate the exponent [tex]\(2 - 4\)[/tex]:

[tex]\[ 2 - 4 = -2 \][/tex]

4. Therefore, the first term becomes:

[tex]\[ \left(\frac{1}{2}\right)^{-2} \][/tex]

5. Recall that [tex]\(\left(\frac{a}{b}\right)^{-n} = \left(\frac{b}{a}\right)^{n}\)[/tex]:

[tex]\[ \left(\frac{1}{2}\right)^{-2} = \left(\frac{2}{1}\right)^{2} = 2^2 = 4 \][/tex]

6. Next, substitute [tex]\(x\)[/tex] and [tex]\(y\)[/tex] into the second term [tex]\(\left(\frac{y}{x}\right)^{y-x}\)[/tex]:

[tex]\[ \left(\frac{y}{x}\right)^{y-x} = \left(\frac{4}{2}\right)^{4-2} \][/tex]

7. Calculate the fraction inside the parentheses:

[tex]\[ \frac{4}{2} = 2 \][/tex]

8. Now calculate the exponent [tex]\(4 - 2\)[/tex]:

[tex]\[ 4 - 2 = 2 \][/tex]

9. Therefore, the second term becomes:

[tex]\[ 2^2 = 4 \][/tex]

10. Finally, add the two terms together:

[tex]\[ 4 + 4 = 8 \][/tex]

Thus, the solution to the expression is:

[tex]\[ \boxed{8} \][/tex]