Question

If 5a + 1/7a = 5, then let's find the value of 25a²+1/49a²

​

Answer 1

Answer:

Multiply both side by 3/5.

(

5

3

)5a+(

5

3

)(

3

1

a)=(

5

3

)5

=> 3a+(

5

1

a)=3

Squaring both sides,

9a

2

+(

25a

2

1

)+(

5

6

)=9 {using (a+b)

2

=a

2

+b

2

+2ab)

=> 9a

2

=(

25a

2

1

)=

5

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