Question

 Find the factors of 3x2 − 33x + 84

Answer 1

For these ones I just play around with what I can divide 84 by to equal -33 in the middle. I decided to divide 84 by 4 because it was an even number. 

84/4=21

21+ (3*4)= 33

Answer: (x-4)(3x-21)

Answer 2

Answer:  The factors of the given expressions are 3, (x-7) and (x-4).

Step-by-step explanation:  We are given to find the factors of the following quadratic expression :

$E=3x^2-33x+84~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)$

To find the factors of the given expression, we need to find two integers with sum -33 and product 252.

From (i), we have

$E\\\\=3x^2-33x+84\\\\=3x^2-21x-12x+84\\\\=3x(x-7)-12(x-7)\\\\=(x-7)(3x-12)\\\\=3(x-7)(x-4).$

Thus, the factors of the given expressions are 3, (x-7) and (x-4).