8x^3+6x^2-20x PLS FACTORIZE THIS I'LL MARK BRAINLIEST!
Answers
Answer:
whether x – 4 is a factor of:
–2x5 + 6x4 + 10x3 – 6x2 – 9x + 4
For x – 4 to be a factor, you must have x = 4 as a zero. Using this information, I'll do the synthetic division with x = 4 as the test zero on the left:
completed division
Since the remainder is zero, then x = 4 is indeed a zero of –2x5 + 6x4 + 10x3 – 6x2 – 9x + 4, so:
Yes, x – 4 is a factor of –2x5 + 6x4 + 10x3 – 6x2 – 9x + 4
Find all the factors of 15x4 + x3 – 52x2 + 20x + 16 by using synthetic division.
Remember that, if x = a is a zero, then x – a is a factor. So use the Rational Roots Test (and maybe a quick graph) to find a good value to test for a zero (x-intercept). I'll try x = 1:
completed division
This division gives a zero remainder, so x = 1 must be a zero, which means that x – 1 is a factor. Since I divided a linear factor (namely, x – 1) out of the original polynomial, then my result has to be a cubic: 15x3 + 16x2 – 36x – 16. So I need to find another zero before I can apply the Quadratic Formula. I'll try x = –2:
completed division
Since I got a zero remainder, then x = –2 is a zero, so x + 2 is a factor. Plus, I'm now down to a quadratic, 15x2 – 14x – 8, which happens to factor as:
(3x – 4)(5x + 2)
Then the fully-factored form of the original polynomial is:
15x4 + x3 – 52x2 + 20x + 16
= (x – 1)(x + 2)(3x – 4)(5x + 2)
Given that x = -3 + sqrt(11) is a zero of x4 + 6x3 – 7x2 – 30x + 10, fully solve the
equation x4 + 6x3 – 7x2 – 30x + 10 = 0.
Since they have given me one of the zeroes, I'll use synthetic division to divide it out:
completed division
Answer:
2x ( x + 2 ) ( 4x - 5 )
Step-by-step explanation:
8x^3+6x^2-20x
= 2x ( 4x^2 + 3x -10 )
= 2x ( 4x^2 + 8x - 5x - 10 )
= 2x ( 4x ( x + 2) - 5 ( x + 2 ) )
= 2x ( x + 2 ) ( 4x - 5 )
Hope it helps