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2 votes
What is a perfect square? Why is
x^(2) + 8x +16 a perfect square?

2 Answers

12 votes

Answer:

It is a perfect square. Explanation below.

Step-by-step explanation:

Perfect squares are of the form

(

a

+

b

)

2

=

a

2

+

2

a

b

+

b

2

. In polynomials of x, the a-term is always x.(

(

x

+

c

)

2

=

x

2

+

2

c

x

+

c

2

)

x

2

+

8

x

+

16

is the given trinomial. Notice that the first term and the constant are both perfect squares:

x

2

is the square of x and 16 is the square of 4.

So we find that the first and last terms correspond to our expansion. Now we must check if the middle term,

8

x

is of the form

2

c

x

.

The middle term is twice the constant times x, so it is

2

×

4

×

x

=

8

x

.

Okay, we found out that the trinomial is of the form

(

x

+

c

)

2

, where

x

=

x

and

c

=

4

.

Let us rewrite it as

x

2

+

8

x

+

16

=

(

x

+

4

)

2

. Now we can say it is a perfect square, as it is the square of

(

x

+

4

)

.

User Adelle
by
4.2k points
10 votes

A perfect square is a number that can be expressed as the square of an integer. In algebra, a perfect square is an expression that can be factored into the square of a binomial.
x^2+8x+16 is a perfect square because it can be factored into
(x+4)^2.

A perfect square is a number that can be expressed as the square of an integer.

For example, 4 is a perfect square because it can be expressed as
2^2, or 9 is a perfect square because it can be expressed as
3^2.

In algebra, a perfect square is an expression that can be factored into the square of a binomial, such as
(x+2)^2.

In the equation
x^2+8x+16, we can see that it can be factored into
(x+4)^2, which is the square of the binomial (x+4).

This makes
x^2+8x+16 a perfect square.

User Frederik Hoeft
by
4.2k points