Question 885645
if the zeroes are -3 and -7, you can find the factors by doing the following:

first zero:
x = -3
add 3 to both sides of this equation to get:
x + 3 = 0

second zero:
x = -7
add 7 to both sides of this equation to get:
x + 7 = 0


so far your factors are:
(x + 3) * (x + 7)


put these factors into equation form and you get:
f(x) = (x + 3) * (x + 7)


since the equation goes through the point (-5,4), then when x = -4 you should get f(x) = -5.


replacing x with -5, you get f(x) (-5 + 3) * (-5 + 7) which is equal to (-2) * (2) which is equal to (-4).


this is the right value but the wrong sign.


what this means is you need another factor of (-1) to make sure you get the right value.


your factors become:
f(x) = (-1) * (x + 3) * (x + 7)


now when you replace x with -5, you get f(x) = (-1) * (-2) * (2) which is equal to (-1) * (-4) which is equal to 4.


your factors are:
(-1) * (x + 3) * (x + 7)