Представьте в виде произведения
(10x + 3y)² - (8x + 4y)(8x - 4y) = 100x² + 60xy + 9y² - 64x² + 16y² =
= 36x² + 60xy + 25y² = (6x + 5y)² = (6x + 5y)(6x + 5y)
(10x+3y)²-(8x+4)*(8x-4)=100x²+60xy+9y²-(64x²-16y²)=
=100x²+60xy+9y²-64x²+16y²=36x²+60xy+25y²=
=(6x)²+2*6x*5y+(5y)²=(6x+5y)².