Answer:
[tex]0.09y^2 - 0.81 = (0.3y+0.9)(0.3y-0.9)[/tex]
Step-by-step explanation:
The difference of squares formula gives us
[tex]a^2 - b^2 = (a+b)(a-b)[/tex]
(you can multiply this out to confirm)
[tex]0.09y^2 = (0.3y)^2[/tex]
and
[tex]0.81 = 0.9^2[/tex]
Thus, by the difference of squares formula
[tex]0.09y^2 - 0.81 = (0.3y+0.9)(0.3y-0.9)[/tex]
