Fine the product mentally. [(x+1) (x-1)^2

x^4 - 2x^2 +1

Step-by-step explanation:

[(x+1) (x-1)]^2

We notice that this is the difference of squares

a^2 -b^2 = (a+b) (a-b)

Since we have (x+1) (x-1) , it simplifies to (x^2 -1)

[x^2-1]^2

We know  (a-b)^2  is a^2 -2ab +b^2

[x^2-1]^2 = x^4 - 2x^2 +1

b. 10=9.1+0.2x

step-by-step explanation:

that's it

i think the answer is b.

step-by-step explanation:

not 100% sure though.