Question

Find the product using suitable identity
a. (7mn+1)(7mn+1)

Answer 1

`49m^2n^2 + 14mn + 1`

Explanation:

this is equivalent
`(7mn+1)(7mn+1)<->(7mn+1)^2`

identity of squaring this kind of equation is:

`(a+b)^2 = a^2 + 2ab + b^2`

here, a = 7mn and b = 1

so, this expands to
`49m^2n^2 + 14mn + 1`