Which expression is equivalent to (x4) -5

 (x2 + y2) • (x + y) • (x - y)

Step-by-step explanation:

Trying to factor as a Difference of Squares :

1.1      Factoring:  x4-y4  

Theory : A difference of two perfect squares,  A2 - B2  can be factored into  (A+B) • (A-B)

Proof :  (A+B) • (A-B) =

        A2 - AB + BA - B2 =

        A2 - AB + AB - B2 =

        A2 - B2

Note :  AB = BA is the commutative property of multiplication.

Note :  - AB + AB equals zero and is therefore eliminated from the expression.

Check :  x4  is the square of  x2  

Check :  y4  is the square of  y2  

Factorization is :       (x2 + y2)  •  (x2 - y2)  

Trying to factor as a Difference of Squares :

1.2      Factoring:  x2 - y2  

Check :  x2  is the square of  x1  

Check :  y2  is the square of  y1  

Factorization is :       (x + y)  •  (x - y)  

Final result :

 (x2 + y2) • (x + y) • (x - y)

0.16 or 16%

step-by-step explanation:

lets take a coin for example.

if you toss it twice, it has a 1/4 chance of landing on heads both times because 1/2 * 1/2 is 1/4.

with the cards, the chance of picking dog is 0.4. having two people pick one is like picking a card twice in a row. so 0.4 * 0.4 is 0.16, or 16%