SOLUTION: If the roots of a cubic equation are: x=-5/2, x=1/4 & x=3. Determine this cubic expression by expansion, with these roots.

Question 66300: If the roots of a cubic equation are: x=-5/2, x=1/4 & x=3. Determine this cubic expression by expansion, with these roots.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
If the roots of a cubic equation are: x=-5/2, x=1/4 & x=3. Determine this cubic expression by expansion, with these roots.
--------------
If those numbers are roots, then:
x+(5/2)=0
or
x-(1/4)=0
or
x-3=0
-------------
Which means:
2x+5=0
or
4x-1=0
or
x-3=0
------------
Taking the product of these you get:
(2x+5)(4x-1)(x-3)=0
(2x^2-2x+20x-5)(x-3)=0
2x^3-2x^2+20x^2-5x-6x^2+6x-60x+15=0
2x^3+12x^2-59x+15=0
----------
Cheers,
Stan H.
RELATED QUESTIONS
a family of quadratic functions has zeros -3 and 5.Which of the following is a member of... (answered by KMST)

The roots of a cubic are x = -2, x = 3, and x = 5. What are the possible factors of the... (answered by stanbon)

The roots of a cubic are x=-2,x=3, and x=5. What arethe possible factors of the cubic?... (answered by KMST)

Given the equation 2^x = x^2 which has 3 real roots: by means of inspection, determine 2... (answered by Alan3354)

``the function f(x)=x(cubed)-2x(squared)-5x+6 has three integer roots 1) Find the... (answered by jim_thompson5910)

the function f(x)=2x(cubed)-2x(squared)-5x+6 has three integer roots 1) Find the tree (answered by solver91311)

use the cubic function f(x)=x^3+x^2-3x+1 to complete the remaining problems 1) what... (answered by stanbon,ewatrrr)

Find a cubic equation with roots 6,-1, and... (answered by MathLover1,It is costly)

Can anyone help me with ANY of these? Please... 1. Solve for the roots by factoring. (answered by solver91311)