can someone help me please i’m really confused
(4a+3)(4a -3)=(4a)²-(3)²=16a²-9
+62 You would do 4a+3 times 4a-3 which gets you $${\mathtt{16}}{\mathtt{\,\times\,}}{{\mathtt{a}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{9}}$$ for the fist part!
Then for the secound part $${{\mathtt{4}}}^{{\mathtt{2}}} = {\mathtt{16}}$$, $${{\mathtt{a}}}^{{\mathtt{2}}}$$ is just $${{\mathtt{a}}}^{{\mathtt{2}}}$$ and $${{\mathtt{3}}}^{{\mathtt{2}}} = {\mathtt{9}}$$ so you get the same eqaution as above!
And finally for the last part there is no working out (simplifying) as it's the answer!
All that the equation is doing is showing you how to go from (4a+3)(4a -3) to a more simplified answer.
+62 You would do 4a+3 times 4a-3 which gets you $${\mathtt{16}}{\mathtt{\,\times\,}}{{\mathtt{a}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{9}}$$ for the fist part!
Then for the secound part $${{\mathtt{4}}}^{{\mathtt{2}}} = {\mathtt{16}}$$, $${{\mathtt{a}}}^{{\mathtt{2}}}$$ is just $${{\mathtt{a}}}^{{\mathtt{2}}}$$ and $${{\mathtt{3}}}^{{\mathtt{2}}} = {\mathtt{9}}$$ so you get the same eqaution as above!
And finally for the last part there is no working out (simplifying) as it's the answer!
All that the equation is doing is showing you how to go from (4a+3)(4a -3) to a more simplified answer.
+118687 (4a+3)(4a -3)=(4a)²-(3)²=16a²-9
If you did this the long way you would get
$$\\(4a+3)(4a -3)\\
=4a(4a-3)+3(4a-3)\\
=(4a)^2-12a+12a-3^2\\
=(4a)^2-3^2\\
=16a^2-9$$
NOW when you have the same thing in both brackets except one has a minus in the middle and the other has a plus in the middle they always work out this way.
They are called a difference of two squares because when they are expanded and simplified you will end up with
the first one squared - the second on squared
so
$$\\(4a+3)(4a -3)\\
=(4a)^2-3^2\\
=16a^2-9$$
Does that help lessen your confusion? 
