how do you find the zeros in functions

Question

anonymous · Answer

$$\frac{ 5(x+2 }{ 3(x-1) (x+7}$$

anonymous · Answer

@phi

phi · Answer

a fraction is 0 if its "top" is zero  (as long as the bottom is not zero at the same time)

anonymous · Answer

i dont get it??

anonymous · Answer

so does the top need to equal to zero, as long as the bottom isnt zero too??

phi · Answer

you have
$$ f(x) = \frac{ 5(x+2) }{ 3(x-1) (x+7)} $$

that will be zero if the numerator is 0.

phi · Answer

example:   0/2  = 0
0/anything = 0   (except 0/0 which is not defined)

phi · Answer

so to answer your question you should find what x value makes (x+2)  zero.

anonymous · Answer

oh ok thank you're very helpful

phi · Answer

in other words, you could write down
5(x+2) = 0

divide both side by 5
x+2 = 0/5
x+ 2 = 0
add -2 to both sides
x= -2

that would make the top zero, so x=-2 is a "zero of your function"