Algbrea 2 Math

Question

(x-9)(3x+7)=0

 

x=???

Answer 1

Given   (x-9)(3x+7) = 0 then either x-9 = 0  or   (3x+7) = 0 

 

Thus, solving these two equations will give the answers

 

x-9 = 9 when x=9

 

3x+7 = 0

3x = -7

x = -7/3

 

thus the answer is x = 9, -7/3

Answer 2

Hi again David;

(x-9)(3x+7)=0

Either...

(0)(3x+7)=0

or

(x-9)(0)=0

If...

x-9=0

x=9

If...

3x+7=0

3x=-7

x=-7/3

Answer 3

Hi David,

 

The way to solve this problem is think about how you can get 0.

 

For example if the problem was (x)(y)=0, then either x or y would have to equal zero.

 

Now back to your question, the same thought process is applied here.

 

(x-9)(3x+7)=0

 

either (x-9)=0 or (3x+7)=0

 

Now just solve each of those small equations and you will get the two values of x that make (x-9)(3x+7)=0 true!