Разложите на множители:
а) 3a + 3b + c(a + b);
б) 2(m + n) + km + kn;
в) by + 4(x + y) + bx;
г) a(x − y) + bx − by;
д) 3b − 3c + a(b − c);
е) ab + 2(b − d) − ad.
3a + 3b + c(a + b) = (3a + 3b) + c(a + b) = 3(a + b) + c(a + b) = (a + b)(3 + c)
2(m + n) + km + kn = 2(m + n) + (km + kn) = 2(m + n) + k(m + n) = (m + n)(2 + k)
by + 4(x + y) + bx = 4(x + y) + (by + bx) = 4(x + y) + b(y + x) = (x + y)(4 + b)
a(x − y) + bx − by = a(x − y) + (bx − by) = a(x − y) + b(x − y) = (x − y)(a + b)
3b − 3c + a(b − c) = (3b − 3c) + a(b − c) = 3(b − c) + a(b − c) = (b − c)(3 + a)
ab + 2(b − d) − ad = 2(b − d) + (ab − ad) = 2(b − d) + a(b − d) = (b − d)(2 + a)