Question

Simplify 3x (4x-5) + 3 and find its values for (i) x = 3, (ii) x = -2
(5marks)​

Answer 1

Answer:

(I) 66

(ii) 81

Step-by-step explanation:

3x (4x-5) + 3

(i) x = 3

=3(3)[4(3)-5]+3

=9[12-5]+3

=9[7]+3

=63+3

=66

3x (4x-5) + 3

(ii) x = -2

=3(-2)[4(-2)-5]+3

=-6[-8-5]+3

=-6[-13]+3

=78+3

=81

Answer 2

Step-by-step explanation:

3x*4x-3x*5+3

12x^2-15x+3

(1) x = 3

12*3*3-15*3+3

108-45+3

111-45

66

(2) x = -2

(12*-2*-2)-(15*-2)+3

48+30+3

48+33

81