Respuesta :
Expanding the given expressions using Foil:
1)(–7x + 4)(–7x + 4) =[tex]7x^{2}-28x-28x+16=49x^{2}-56x+16[/tex]
2) (–7x + 4)(4 – 7x)=[tex]-28x+49x^{2}+16-28x=49x^{2}-56x+16.[/tex]
3)(–7x + 4)(–7x – 4)=[tex]49x^{2}+28x-28x-16[/tex]=[tex]49x^{2}-16.[/tex]
4)(–7x + 4)(7x – 4)=[tex]49x^{2}+28x+28x-16=49x^{2}+56x-16.[/tex]
The third option that is (–7x + 4)(–7x – 4) is difference of two squares.
