What is the product of the roots of the equation 5x^2-25+10x?

Question

plz help soon. 

Answer 1

For an equation of the form Ax² + Bx + C = 0 (A≠0), the product of the roots is C/A.

 

So, if 5x² + 10x - 25 = 0, product of roots = -25/5 = -5.  

Answer 2

y = 5x² + 10x - 25

 

If you take the factored form of a quadratic, where p and q are the roots, and multiply it out:

 

y = a(x-p)(x-q)

y = ax² - a(p+q)n + apq

 

You see that the constant term, -25 in your case, is equal to apq where a = 5 and pq is the product of the roots:

 

c = apq

-25 = (-5)pq

25/(-5) = pq

-5 = pq

Answer 3

I assume you meant to say that the expression = 0. It helps to first write the equation in standard form, and then simplify it.

 

5x² + 10x - 25 = 0

 

x² + 2x - 5 = 0

 

x = {-2 ± √[2² - 4(1)(-5)]} / [2(1)]

 

Simplify this, and you will have the 2 roots.  You can finish from here.