104
punti
Livello 1
La n. 3 grazie
3)
$\small \left(-2b\right)^2+\left(2a-3b+\dfrac{1}{2}\right)^2-\left(\dfrac{1}{2}a+3b\right)^2+(a-2b)(a+2b)+3b(5a+1)-\dfrac{1}{4}=$
$\small = \cancel{4b^2}+\left(2a-3b+\dfrac{1}{2}\right)\left(2a-3b+\dfrac{1}{2}\right) -\left(\dfrac{1}{4}a^2+3ab+9b^2\right) + a^2+\cancel{2ab}-\cancel{2ab}-\cancel{4b^2}+15ab+3b-\dfrac{1}{4}=$
$\small = 4a^2-6ab+a-6ab+9b^2-\dfrac{3}{2}b+a-\dfrac{3}{2}b+\cancel{\dfrac{1}{4}} -\dfrac{1}{4}a^2-3ab-9b^2 + a^2+15ab+3b-\cancel{\dfrac{1}{4}}=$
$\small = \left(4-\dfrac{1}{4}+1\right)a^2+(-6-6-3+15)ab+(1+1)a+\left(-\dfrac{3}{2}-\dfrac{3}{2}+3\right)b=$
$\small = \left(\dfrac{16-1+4}{4}\right)a^2+\cancel{0ab}+2a+\left(\dfrac{-3-3+6}{2}\right)b=$
$\small = \dfrac{19}{4}a^2+2a+\cancel{0b}=$
$\small = \dfrac{19}{4}a^2+2a$
68276
punti
Genius I