Question

How do you factor completely `49x^2 - 25y^2`?

Answer 1

`(7x-5y)(7x+5y)`

Explanation:

Given: `49x^2-25y^2`

Apply the identity: `a^2-b^2=(a-b)(a+b)`

Here, `a^2=49x^2,b^2=25y^2`

`:.a=sqrt(49x^2)=7x,b=sqrt(25y^2)=5y`

And so,

`49x^2-25y^2=(7x-5y)(7x+5y)`