Answer :
We are asked to factorize the following trinomial (trinomial means three terms)
[tex]49x^2-70x+25[/tex]Let us factorize the above trinomial.
It can be factored by using the perfect square rule
[tex]a^2-2ab+b^2=(a-b)^2[/tex][tex]\begin{gathered} 49x^2=(7x)^2 \\ 25=5^2 \\ 70x=2(7x)(5) \end{gathered}[/tex]So, the factorized expression is
[tex]49x^2-70x+25=(7x)^2-2(7x)(5)+(5)^2=(7x-5)^2[/tex]Therefore, the answer is
[tex](7x-5)^2=(7x-5)(7x-5)[/tex]