Answer:
[tex]23-4\sqrt{15}[/tex]
Step-by-step explanation:
So we want to simplify:
[tex](2\sqrt5-\sqrt3)^2[/tex]
Note that this is in the format:
[tex](a-b)^2[/tex]
And we know that this is the same as:
[tex](a-b)^2=a^2-2ab+b^2[/tex]
Let 2√5 be a and let √3 be b. Thus:
[tex](2\sqrt5-\sqrt3)^2\\=(2\sqrt5)^2-2(2\sqrt5)(\sqrt3)+(\sqrt3)^2[/tex]
Simplify:
[tex]=(4(5))-4(\sqrt5)(\sqrt3)+(3)\\=20-4\sqrt{15}+3\\=23-4\sqrt{15}[/tex]
And this cannot be simplified any further.
