1) (a+b)(c-d) = ac - ad + bc - bd = ac + bc - ad - bd
2) 5ах - 6bx - 5ay + 6by = 5а(х - у) - 6b(х - у) = (5а - 6b)(х - у)
1) (a+b)(c-d) = ac - ad + bc - bd = ac + bc - ad - bd
2) 5ах - 6bx - 5ay + 6by = 5а(х - у) - 6b(х - у) = (5а - 6b)(х - у)