а) 5a(b+c) - 10(b+c) = 5a(b+c) - 10(b+c) = 5ab + 5ac - 10b - 10c = 5a(b+c) - 10(b+c) = 5a(b+c) - 10(b+c) = (5a-10)(b+c)
б) 2a-ac+2b-cb = a(2-c) + b(2-c) = (a+b)(2-c)
а) 5a(b+c) - 10(b+c) = 5a(b+c) - 10(b+c) = 5ab + 5ac - 10b - 10c = 5a(b+c) - 10(b+c) = 5a(b+c) - 10(b+c) = (5a-10)(b+c)
б) 2a-ac+2b-cb = a(2-c) + b(2-c) = (a+b)(2-c)