Which of the following polynomials represents a difference of squares? x^2-1,x^2-8,4x^2+16,9x^2-18

Step-by-step explanation:

we know that

Every difference of squares problem can be factored as follows:

If the polynomial represent a difference of squares every number must be a perfect square (Remember that a number is a perfect square if its square root is an integer.)

Verify each case

case 1) we have

In this case both numbers are perfect square

so

therefore

The polynomial represent a difference of squares

case 2) we have

In this case 8 is not a perfect square

therefore

The polynomial not represent a difference of squares

case 3) we have

In this case both numbers are perfect square

but is a sum of squares

therefore

The polynomial not represent a difference of squares

case 4) we have

In this case 2 is not a perfect square

therefore

The polynomial not represent a difference of squares

d is the correct answer

step-by-step explanation:

x= 8 because 3x = 3 * 8, and 3*8 = 24