resolve into factor 27 x power 4- 8 x
Answers
Answer:
STEP
1
:
Equation at the end of step 1
33x4 - 8x
STEP
2
:
STEP
3
:
Pulling out like terms
3.1 Pull out like factors :
27x4 - 8x = x • (27x3 - 8)
Trying to factor as a Difference of Cubes:
3.2 Factoring: 27x3 - 8
Theory : A difference of two perfect cubes, a3 - b3 can be factored into
(a-b) • (a2 +ab +b2)
Proof : (a-b)•(a2+ab+b2) =
a3+a2b+ab2-ba2-b2a-b3 =
a3+(a2b-ba2)+(ab2-b2a)-b3 =
a3+0+0+b3 =
a3+b3
Check : 27 is the cube of 3
Check : 8 is the cube of 2
Check : x3 is the cube of x1
Factorization is :
(3x - 2) • (9x2 + 6x + 4)
Trying to factor by splitting the middle term
3.3 Factoring 9x2 + 6x + 4
The first term is, 9x2 its coefficient is 9 .
The middle term is, +6x its coefficient is 6 .
The last term, "the constant", is +4
Step-1 : Multiply the coefficient of the first term by the constant 9 • 4 = 36
Step-2 : Find two factors of 36 whose sum equals the coefficient of the middle term, which is 6 .
-36 + -1 = -37
-18 + -2 = -20
-12 + -3 = -15
-9 + -4 = -13
-6 + -6 = -12
-4 + -9 = -13
For tidiness, printing of 12 lines which failed to find two such factors, was suppressed
Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored
Final result :
x • (3x - 2) • (9x2 + 6x + 4)