Use direct method to ecaluate the following products :
(i) (x + 8)(x + 3)
(ii) (y + 5)(y - 3)
(iii) (a- 8)(a+ 2)
(iv) (b - 3)(b - 5)
(v) (3x - 2y)(2x + y)
(vi) (5a + 16)(3a -7)
(vii) (8 - b)(3 + b)
Simplify these expressions and find their values if x = 3, a = − 1, b = − 2.
(i) 3x − 5 − x + 9 (ii) 2 − 8x + 4x + 4
(iii) 3a + 5 − 8a + 1 (iv) 10 − 3b − 4 − 5b
(v) 2a − 2b − 4 − 5 + a