If x = 2^74 - 2^70, what is the largest prime factor of x?

Question

If  x = 2^{74} - 2^{70} , what is the largest prime factor of x?

A. 2
B. 3
C. 5
D. 7
E. 11

raks85 · Answer

2^74-2^70
= 2^70(2^4-1)
= 2^70 (16-1)
= 2^70*3*5

Hence, the largest prime factor is 5.

So, the correct answer is option (C).

bonion · Answer

x = 2^74 - 2^70
x = 2^70 ( 2^4 - 2^0)
x = 2^70 (16 - 1)
x = 2^70 * 15
x = 2^70 * 3^1 * 5^1
The largest prime factor is 5.

PKN · Answer

Given,  x = 2^{74} - 2^{70} 
Factor out the common term  2^{70} ,
 x=2^{70}(2^4-1)=2^{70}*15 
Prime factors are: 2,3,and 5
largest prime factor:5

Ans. (C)

KSBGC · Answer

x = 2^{74} - 2^{70}

=  2^{70}(2^4 - 1)

=  2^{70} * 15

=  2^{70} * 3*5

So, 5 is the greatest prime factor.

The best answer is C.

Abhishek009 · Answer

x = 2^{74} - 2^{70}

Or,  x = 2^{70}(2^4 - 1)

Or,  x = 2^{70}(15)

Or,  x = 2^{70}(3*5) , Thus the largest prime factor is 5, Answer must be (C)

JeffTargetTestPrep · Answer

We first factor 2^70 from both terms. Simplifying, we have:

2^70(2^4 - 1)

2^70 x 15

2^70 x 3 x 5

The largest prime factor is 5.

Answer: C

Abhishek009 · Answer

x = 2^{74} - 2^{70}

Or,  x = 2^{70}(2^{4} - 1)

Or,  x = 2^{70}(16 - 1)

Or,  x = 2^{70}*3*5 , So, Largest prime factor of x is 5, Answer must be (C)

Kinshook · Answer

Asked: If  x = 2^{74} - 2^{70} , what is the largest prime factor of x?

x = 2^{74} - 2^{70} = 2^{70}(2^4-1) = 2^{70}*(16-1) = 2^{70}*3*5

IMO C

Posted from my mobile device

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If x = 2^74 - 2^70, what is the largest prime factor of x?

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If x = 2^74 - 2^70, what is the largest prime factor of x?

Prep Toolkit

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