Find the coefficient of x2 in (x - 1)(9x2 - 3x + 1) :-
a) 12
b) -3
c) 9
d) -12
Answers
Answered by
5
Answer:
9 is the coefficient of x²
Answered by
1
Answer:
The correct answer is option(d) -12
Step-by-step explanation:
To find,
The coefficient of x², in (x - 1)(9x² - 3x + 1)
Recall the property
Distributive property
a(b+c) = ab +ac
Solution
Given expression is (x - 1)(9x² - 3x + 1)
Applying distributive property
(x - 1)(9x² - 3x + 1) = x(9x² - 3x + 1) - 1(9x² - 3x + 1)
= 9x³ -3x² +x - 9x² + 3x - 1
= 9x³ -12x² +4x - 1
(x - 1)(9x² - 3x + 1) = 9x³ -12x² +4x - 1
The coefficient of x² in 9x³ -12x² +4x - 1 = -12
∴The coefficient of x², in (x - 1)(9x² - 3x + 1) = -12
The correct answer is option(d) -12
#SPJ3
Similar questions