По формуле:
(a-b)^2= a^2-2ab+b^2
1) (25x-8)(25x+8)= (25x)^2-8^2= 625x^2-64
2) (5x-8)(5x+8)= (5x)^2-8^2= 25x^2-64
3) (5x-4)(5x+4)= (5x)^2-4^2= 25x^2-16
4) (5x-8)^2= (5x)^2 -2×5x×8+8^2= 25x^2-80x+64
По формуле:
(a-b)^2= a^2-2ab+b^2
1) (25x-8)(25x+8)= (25x)^2-8^2= 625x^2-64
2) (5x-8)(5x+8)= (5x)^2-8^2= 25x^2-64
3) (5x-4)(5x+4)= (5x)^2-4^2= 25x^2-16
4) (5x-8)^2= (5x)^2 -2×5x×8+8^2= 25x^2-80x+64