SOLUTION: 9p^2-15p-6=0

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 9p^2-15p-6=0      Log On


   



Question 846604: 9p^2-15p-6=0
Found 2 solutions by Fombitz, josh_jordan:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
9p%5E2-15p-6=0
3%283p%5E2-5p-2%29=0
%283p%2B1%29%28p-2%29=0
Two solutions:
3p%2B1=0
3p=-1
p=-1%2F3
and
p-2=0
p=2

Answer by josh_jordan(263) About Me  (Show Source):
You can put this solution on YOUR website!
Since this is a quadratic equation, let's see if we can factor the equation to determine the value of p, since factoring is generally the easiest. The first thing we can do is factor out a 3, since all of the numbers in the equation are divisible by 3:

3%283p%5E2-5p-2%29=0

We can discard the 3, since 3 does not equal 0. This leaves us with

3p%5E2-5p-2=0

Since 3 has only 2 factors: 3 and 1 (or -3 and -1) and -2 only has two factors: -2 and 1 (or 2 and -1), we can easily factor this equation:

%283p%2B1%29%28p-2%29=0

Now that we've factored, we can set each factor to 0 and solve for p:

3p + 1 = 0 ----->

3p = -1 ----->

p = -1/3

AND

p - 2 = 0 ----->

p = 2

We can verify each value by replacing p with each value in the original equation. We will see both values, when replacing for p, give us 0. So

p = -1/3 and 2