Question

A certain quadratic function has the factors
(2x - 5)
and
(3x + 4)
. What are the zeros of the function?
a. x=-2 and x=-3
b. x=2/5 and x= 4/3
c. x=5 and x=-4
d. x=5/2 and x = -4/3

Answer 1

Answer:

D

Step-by-step explanation:

If those two functions are the factors of a quadratic, then each of them can be equated to 0 to find the roots. Sometimes the roots are called the zeros.

2x - 5 = 0                       Add 5 to both sides

2x - 5 + 5 = 0 + 5           Combine

2x = 5                             Divide both sides by 2

2x/2 = 5/2

x = 5/2

You don't really have to find the other factor's 0 point. There is only 1 option that makes x = 5/2. On a test, it is important to take short cuts and save time.  I'll find the other root anyway because this is not a test.

3x + 4 = 0                           Subtract 4 from both sides

3x + 4-4 = 0 - 4                  Combine

3x = - 4                               Divide both sides by 3

3x/3 = - 4/3

x = - 4/3