SOLUTION: I need help please: {{{2x^2+9x-5=0}}} Thanks.
Algebra.Com
Question 8445: I need help please: Thanks.
Found 3 solutions by bonster, drglass, JimMarshall:
Answer by bonster(299) (Show Source): You can put this solution on YOUR website!
(2x-1)(x+5)=0
if 2x-1=0
2x=1
x=1/2
if x+5=0
x=-5
Answer by drglass(89) (Show Source): You can put this solution on YOUR website!
There a several ways to solve this. The easiest is to use the quadratic equation, however I suspect, given the results I get from the quadratic equation, that you are actually required to factor the problem, so, how do you do this?
First, notice that you result will have to have the form
.
The goal is to find the values for a and b. To do this notice that according to the equation,:
a + 2b = 9 and
ab = -5
There are four ways to make ab = -5:
a b ab
5 -1 -5
-5 1 -5
1 -5 -5
-1 5 -5
One of these combinations must also give us 9, so let's consider what happens with these combinations when we apply them to a + 2b:
a b ab
5 -1 3
-5 1 -3
1 -5 -9
-1 5 9
The last combination gives us the value we want. This means a = -1 and b = 5 works. So the factorization of is .
This expression is zero when 2x - 1 = 0 or when x + 5 = 0. So the values of x that make the expression equal to zero are x = 1/2 and x = -5.
You can check this by replacing these values in the expression.
Answer by JimMarshall(82) (Show Source): You can put this solution on YOUR website!
(2x-1)(x+5)=0
if 2x-1=0
2x=1
x=1/2
if x+5=0
x=-5
Ans
RELATED QUESTIONS
Can you help please help me? I need to find the difference in simplest form.... (answered by stanbon)
Need help on solving these two problems, thanks =0)
1. -9x+20=-2x
2. 2x^2-5=3x (answered by corrie21)
please help with this,
Find ALL solutions of the equation. I need to show all possible (answered by adamchapman)
Please help me. I am confused. How do I solve these by factoring?
3x^2 -2x = 0
and
(answered by ankor@dixie-net.com)
I need help with this: 3x^2+9x-30=0... (answered by josmiceli,MathTherapy)
Please!! I need help to solve by completing the square:
2x^2 -9x + 4 = 0
and
4... (answered by stanbon)
Find a quadratic equation with roots 5 and -1/2.
A. 2x^2+9x-5=0
B. 2x^2-9x+5=0
C.... (answered by stanbon,checkley71)
please help me factor the following completely:
2x^2-9x-5... (answered by solver91311)
I need help with this: 2x^2+5=77... (answered by ikleyn)