Question 355708
(2t+3)^2 - (t-1)(t+1)


(2t+3)^2-(t^2-1) .............( (a+b)(a-b)= a^2-b^2) here a =t & b =1)
(4t^2+12t+9)-(t^2-1)...........( (a+b)^2 = a^2+2ab+b^2; a= 2t and b =3)
4t^2+12t+9-t^2+1
group the similar terms & simplify
4t^2-t^2+12t+9+1
3t^2+12t+10
...
In such problems first solve the terms in the brackets and then simplify
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