Пошаговое объяснение:
1) (a + 2b)² - (3c + 4d)² = (a + 2b - 3c - 4d)(a + 2b + 3c + 4d);
2)(x-y)^2-(m+n)^2=(x-y-m-n)(x-y+m+n);
3) (m - 2n)² - (2p - 3q)² = (m - 2n - (2p - 3q))(m - 2n + 2p - 3q) = (m - 2n - 2p + 3q)(m - 2n + 2p - 3q);
4) (2a-3c)²-(4b+5d)²=(2a-3c3(4b+5d))(2a-3c+4b+5d)=(2a-3c-4b-5d)(2a-3c+4b+5d)
5) 9(m + n)² - (m - n)² = (3(m + n))² - (m - n)² = (3(m + n) - (m - n))(3(m + n) + m - n) = (3m + 3n - m + n)(3m + 3n + m - n) = (2m + 4n)(4m + 2n) = 2(m + 2n) · 2(2m + n) = 4(m + 2n)(2m + n);
6) 4(a-b)²-(a+b)²=(2(a-b)-(a+b))(2(a-b)+a+b+)=(2a-2b-a-b)(2a-2b+a+b)=(a-3b)(3a-b)
7) 16(a + b)² - 9(x + y)² = (4(a + b))² - (3(x + y))² = (4a + 4b - (3x + 3y))(4a + 4b + 3x + 3y) = (4a + 4b - 3x - 3y)(4a + 4b + 3x + 3y).
8) 9(a-b)²-4(x-y)²=(3(a-b)-2(x-y))(3(a-b)+2(x-y))=(3a-3b-2x+2y)(3a-3b+2x-2y)
периметр = 2 *7 + 2* 6 = 26