Exponents and Powers | Exponents and Powers - Exercise

Question

$\text { The value of }(2 / 5)^{-2} \text {is: }$

(a) 4/5 (b) 4/25 (c) 25/4 (d) 5/2

Solution
Transcript

"hello students my name is rabbit singh and i welcome you all to leader learning homework one of india's best online classes now today in this video we have a question that is based on the topic of exponents and numbers the question says the value of 2 upon 5 whole to the power minus 2 is so we have four options out of these four options we have to select the correct one so let us solve the question the question is 2 upon 5 to the power -2 now if you will change this minus 2 to plus 2 it will become 5 upon 2 squared this is the property where you are changing minus 2 so you will reverse it like 5 will go in the numerator and 2 will go in the denominator now 5 squared divided by 2 squared so that is 25 by 4 so for this question answer is option c that is 25x4 i hope you have understood the concept very clearly but still if you have any doubt do comment in the comment box and please like and subscribe our channel follow thank you"

Accepted Answer

(c) 25/4

Explanation: By the law of exponent we know:

$\mathrm{a}^{-\mathrm{n}}=1 / \mathrm{a}^{\mathrm{n}}$

$\text { Hence, }(2 / 5)^{-2}=1 /(2 / 5)^{2}=1 /(4 / 25)=25 / 4$

Exponents and Powers | Exponents and Powers - Exercise

Chapters in Mathematics Exemplar Problems - class 8

Exercises in Exponents and Powers

Question 6