(3x - 1)(ax + b) = 12x² - 19x + c
Work out the values of a, b and c.

a = 4, b = - 5, c = 5

Step-by-step explanation:

Expand the product of factors on the left side and compare like terms on both sides.

(3x - 1)(ax + b) ← expand using FOIL

= 3ax² + 3bx - ax - b

= 3ax² + (3b - a)x - b

Equating coefficients of like terms with 12x² - 19x + c , then

3a = 12 ( divide both sides by 3 )

a = 4

3b - a = - 19

3b - 4 = - 19 ( add 4 to both sides )

3b = - 15 ( divide both sides by 3 )

b = - 5

c = - b = - ( - 5) = 5

the answer i think is a)

step-by-step explanation:

answer is the third choice:

3x^5+4x^4+x^3+2x^2-10x-7=0

step-by-step explanation: