Question

A wire of length 300m and area of cross section 1mm^2 has a resistance of 3kohms. Find the resistivity of the material...​

Answer 1

Answer:

Question :

If 3x-y = 12 ,what is the value \frac{8{}^{x}}{2{}^{y}}

2

y

8

x

Formulas :

1)a {}^{m} \times a {}^{n} = a {}^{m + n}1)a

m

×a

n

=a

m+n

2) \frac{a {}^{m} }{a {}^{n} } = a {}^{m - n}2)

a

n

a

m

=a

m−n

3)a {}^{m} \times b {}^{m} = (ab) {}^{m}3)a

m

×b

m

=(ab)

m

Solution :

Given: \sf\:3x-y=123x−y=12

We have to find the value of \frac{8{}^{x}}{2{}^{y}}

2

y

8

x

_______________________

\sf \dfrac{8 {}^{x} }{2 {}^{y} }

2

y

8

x

= \sf \dfrac{(2 {}^{3} ) {}^{x} }{2 {}^{y} }=

2

y

(2

3

)

x

= \sf \dfrac{2 {}^{3x} }{2 {}^{y} }=

2

y

2

3x

we know that \bf\:\frac{a{}^{m}}{a{}^{n}}=a{}^{m-n}

a

n

a

m

=a

m−n

= \sf 2 {}^{3x - y}=2

3x−y

\sf\:3x-y=123x−y=12 ( Given )

= 2 {}^{12}=2

12

Therefore, correct option is a)\sf\:2{}^{12}2

12

Thanks