Se lanza un objeto desde una plataforma.
Su altura (en metros), x segundos después del lanzamiento, está modelada por:
h(x)=-5x^2+20x+60h(x)

¿Cuántos segundos después del lanzamiento el objeto llega al suelo?

6 seconds

Step-by-step explanation:

The question in English is

An object is thrown from a platform.

Its height (in meters), x seconds after launch, is modeled by:

h(x)=-5x^2+20x+60

How many seconds after the launch does the object reach the ground?

Let

x ----> the time in seconds

h(x) ---> the height of the object

we have

we know that

When the object hit the ground the height is equal to zero

so

For h(x)=0

we have

The formula to solve a quadratic equation of the form

is equal to

in this problem we have

so

substitute in the formula

The solution is x=6 sec

The he object reach the ground at x=6 seconds

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10