Question

R^3 +4r^2-25r-100 Help

Answer 1

Answer:

The zeroes in this equation are -5, -4, and 5

Step-by-step explanation:

In order to find these, you need to factor by splitting. For this, we separate out the two halves of the equation and pull out the greatest common factor of each. Let's start with the front end.

r^3 + 4r^2

r^2(r + 4)

Now the second half.

-25r - 100

-25(r + 4)

Since what is left in the parenthesis are exactly the same, we can use that parenthesis next to one with what we pulled out.

(r^2 - 25)(r + 4)

And we can further factor the first parenthesis using the difference of two squares

(r^2 - 25)(r + 4)

(r + 5)(r - 5)(r + 4)

Now that we are fully factored, set each parenthesis equal to 0 and solve for x.

r + 5 = 0

r = -5

r - 5 = 0

r = 5

r + 4 = 0

r = -4