The Total solution for NCERT class 6-12
(a) We have 3x(4x тАУ 5) + 3 = 4x ├Ч 3x тАУ 5 ├Ч 3x + 3 = 12x2┬атАУ15x + 3(i) For x = 3, we have12 ├Ч (3)2┬атАУ15 ├Ч 3 + 3 = 12 ├Ч 9 тАУ 45 + 3 = 108 тАУ 42 = 66(b) We have a(a2┬а+a + 1) + 5= (a2┬а├Чa) + (a ├Ч a) + (1 ├Ч a) + 5= a3┬а+a2┬а+a + 5(i) For a = 0, we have= (0)3┬а+(0)2┬а+(0) + 5 = 5(ii) For a = 1, we have= (1)3┬а+(1)2┬а+(1) + 5 = 1 + 1 + 1 + 5 = 8(iii) For a = -1, we have= (-1)3┬а+(-1)2┬а+(-1) + 5 = -1 + 1 тАУ 1 + 5 = 4