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If (5.55)x=(0.555)y=1000(5.55)^x= (0.555)^y = 1000, then the value of 1x−1y\frac{1}{x} - \frac{1}{y} is

Solution

✅ Correct Option: 4

We have: (5.55)x=(0.555)y=1000(5.55)^x = (0.555)^y = 1000

This means we have two separate equations:

(5.55)x=1000(5.55)^x = 1000

(0.555)y=1000(0.555)^y = 1000


When we have an equation like ax=ba^x = b, we can rewrite it as a=b1/xa = b^{1/x}. This form will help us eliminate the common value 1000.

From (5.55)x=1000(5.55)^x = 1000:

5.55=10001/x5.55 = 1000^{1/x} ...(equation 1)

From (0.555)y=1000(0.555)^y = 1000:

0.555=10001/y0.555 = 1000^{1/y} ...(equation 2)


Since both equations equal powers of 1000, dividing them will help us find a relationship between 1x\frac{1}{x} and 1y\frac{1}{y}.

Dividing equation 1 by equation 2:

5.550.555=10001/x10001/y\frac{5.55}{0.555} = \frac{1000^{1/x}}{1000^{1/y}}

Left side: 5.550.555=55555.5=10\frac{5.55}{0.555} = \frac{555}{55.5} = 10

Right side: Using the law of exponents aman=am−n\frac{a^m}{a^n} = a^{m-n}:

10001/x10001/y=1000(1/x−1/y)\frac{1000^{1/x}}{1000^{1/y}} = 1000^{(1/x - 1/y)}

So we have:

10=1000(1/x−1/y)10 = 1000^{(1/x - 1/y)}


To compare exponents, we need the same base on both sides.

Notice that:

10=10110 = 10^1

1000=1031000 = 10^3

So our equation becomes:

101=(103)(1/x−1/y)10^1 = (10^3)^{(1/x - 1/y)}

Using the power rule (am)n=amn(a^m)^n = a^{mn}:

101=103(1/x−1/y)10^1 = 10^{3(1/x - 1/y)}


When am=ana^m = a^n (where a>0a > 0 and $a

eq 1),then), then m = n$.

Since the bases are equal, the exponents must be equal:

1=3(1x−1y)1 = 3\left(\frac{1}{x} - \frac{1}{y}\right)


Dividing both sides by 3:

1x−1y=13\frac{1}{x} - \frac{1}{y} = \frac{1}{3}


When we have two exponential equations with the same result, we can often divide them to create a relationship between the exponents. This technique is particularly useful when dealing with powers of 10, as it allows us to simplify complex exponential relationships.

Answer: 13\frac{1}{3}

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