Matura Matematika B razina 2023. Ljetni rok – Zadatak 23

Za $x=1$ i $y=-2$:
$16\cdot (-2{)}^2+3\cdot 1\cdot (3\cdot 1-8\cdot (-2))$

$9x^2=(3x{)}^2$, $16y^2=(4y{)}^2$ i $24xy=2\cdot 3x\cdot 4y$, pa prema $a^2-2ab+b^2=(a-b{)}^2$:
$9x^2-24xy+16y^2=(3x-4y{)}^2$
Jednako vrijedi i $(4y-3x{)}^2$, jer suprotni brojevi imaju isti kvadrat.