Simplify 3x(4x - 5) + 3 and find its values for (i) x = 3 (ii)
3x(4x - 5) + 3 = 3x X 4x + 3x X (-5) + 3
= (3 x 4) x X x X +3 X (-5) X x +3
= 12 X x2 + (-15) x X +3
= 12x2 - 15x + 3
(i) For x = 3 , 12x2 - 15x + 3 = 12(3)2 - 15(3) + 3
= 12 x 9 - 45 + 3
= 111 - 45 = 66
(ii) For , 12x2 - 15x + 3 =
=
=
=
simplify a(a2 + a + 1) + 5 and find its values for (i) a = 0, (ii) a = 0, and (iii) a = -1.