(5a − 4)²− (2a − 1)(3a + 7)=
=25а²-40а+16-(6а²+14а-3а-7)=
=25а²-40а+16-(6а²+11а-7)=
=25а²-40а+16-6а²-11а+7=19а²-51а+23
(5a − 4)²− (2a − 1)(3a + 7)=
=25а²-40а+16-(6а²+14а-3а-7)=
=25а²-40а+16-(6а²+11а-7)=
=25а²-40а+16-6а²-11а+7=19а²-51а+23