Asked by VRE
hey i can't figure this one out, does anyone know the answer?
Question: Shenika factored the polynomial completely. What is the value of A?
5x3+35x2+6x+42
(5x2+A)(x+B)
A. 1
B. 5
C. 6
D. 7
(if anyone is confused why this question is written weird, i don't know why its like that either)
Question: Shenika factored the polynomial completely. What is the value of A?
5x3+35x2+6x+42
(5x2+A)(x+B)
A. 1
B. 5
C. 6
D. 7
(if anyone is confused why this question is written weird, i don't know why its like that either)
Answers
Answered by
VRE
(and yes, im this bad at math)
Answered by
mathhelper
Nothing at all wrong with this question, nor the way it is written
so you have:
(5x^2+A)(x+B) = 5x^3+35x^2+6x+42 , ..... notice how I wrote the powers.
expand the left side:
5x^3 + 5Bx^2 + Ax + AB
match the terms:
5x^3 <----> 5x^3
5Bx^2 <----> 35x^2 , so 5B = 35, then B = 7
Ax <----> 6x , then A = 6
AB <----> 42 , true since AB = 6*7 = 42
A = 6
B = 7 , so C is your correct choice
check, sub those values into the factored form,
(5x^2+6)(x+7)
= 5x^3 + 35x^2 + 6x + 42 , which is the expanded form given
So, my answer is correct
so you have:
(5x^2+A)(x+B) = 5x^3+35x^2+6x+42 , ..... notice how I wrote the powers.
expand the left side:
5x^3 + 5Bx^2 + Ax + AB
match the terms:
5x^3 <----> 5x^3
5Bx^2 <----> 35x^2 , so 5B = 35, then B = 7
Ax <----> 6x , then A = 6
AB <----> 42 , true since AB = 6*7 = 42
A = 6
B = 7 , so C is your correct choice
check, sub those values into the factored form,
(5x^2+6)(x+7)
= 5x^3 + 35x^2 + 6x + 42 , which is the expanded form given
So, my answer is correct
Answered by
VRE
Ah thanks so much!