Factorise the expression (i) ax² + bx (ii) 7p² + 21q² (iii) 2x³ + 2xy² + 2xz² (iv) am² + bm² + bn² + an² (v) (lm + l) + m + 1 (vi) y(y + z) + 9(y + z) (vii) 5y² - 10yz + 2yz (viii) 10ab + 4a + 5b + 2 (ix) 6xy - y + 6x

(i) ax² + bx = x(ax + b)
(ii) 7p² + 21q² = 7(p² + 3q²)
(iii) 2x³ + 2xy² + 2xz² = 2x(x² + y² + z²)
(iv) am² + bm² + bn² + an² = m²(a + b) + n²(a + b) = (a + b)(m² + n²)
(v) (lm + l) + m + 1 = (l + 1)(m + 1)
(vi) y(y + z) + 9(y + z) = (y + z)(y + 9)
(vii) 5y² - 10yz + 2yz = (y - 2z)(5y + z)
(viii) 10ab + 4a + 5b + 2 = (2a + 1)(5b + 2)
(ix) 6xy - y + 6x = (2y + 1)(3x - 1)