Respuesta :

Perfect Squares

Perfect square formula/rules:

  • [tex]a^2+2ab+b^2=(a+b)^2[/tex]
  • [tex]a^2-2ab+b^2=(a-b)^2[/tex]

Trinomials are often organized like [tex]ax^2+bx+c[/tex].

The b value in this case is c, and it will always equal the square of half of the b value.

  • Perfect square trinomial: [tex]ax^2+bx+(\dfrac{b}{2})^2[/tex]
  • or [tex]ax^2-bx+(\dfrac{b}{2})^2[/tex]

Solving the Question

We're given:

  • [tex]c^2-4c[/tex]

In a trinomial, we're given the [tex]ax^2[/tex] and [tex]bx[/tex] values. a in this case is 1 and b in this case is 4. To find the third value by dividing 4 by 2 and squaring the quotient:

  • 4 ÷ 2 = 2
  • 2² = 4

Therefore, the term that we can add is + 4.

[tex]c^2-4c+4[/tex]

To write this as the square of a bracketed expression, we can follow the rule [tex]a^2-2ab+b^2=(a-b)^2[/tex]:

[tex](c-2)^2[/tex]

Answer

[tex]c^2-4c+4[/tex]

[tex](c-2)^2[/tex]