1) = 2+а+6+3а = 4а+8 = 4(а+2)2) = 3 - а+6 - 2а = 9 - 3а = 3(3 - а)3) = (m - n)(1 - 5) = - 4(m - n) = 4(n - m)4) = (x - y)(1 - 4) = - 3(x - y) = 3(y - x)5) = (a+b)(4b+1)6) = (x+y)(5x+1)7) = (x-y)(a+1)8) = (m - n)(c+1)9) = (a - b)+2(a - b) = (a - b)(1+2) = 3(a -b)10) = (c - d)(1+3) = 4(c - d)11) = 2(a - b)+c(a - b) = (a - b)(2+c)12) = (c - d)(3 - a)13) смотри 1114) = (c - d) (3 +a)15) = (x - e)(1+a)16) = (m+n)(1+b) 17) = (x - y)(2+a)18) = 3(m - n) - b(m - n) = (m - n)(3 - b)19) = ([x+y)(2 - a)20) = (m+n)(3 - b)