SOLUTION: 1. x^2 + 2x -15 = 0 2. 4x^2 + 32x +15 = 0 3. -2x^2 + x +1 = 0 4. 2x^2 +7x + 0 5. -2x^2 +110x + 9 = 0

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Question 798306: 1. x^2 + 2x -15 = 0
2. 4x^2 + 32x +15 = 0
3. -2x^2 + x +1 = 0
4. 2x^2 +7x + 0
5. -2x^2 +110x + 9 = 0

Found 2 solutions by harpazo, Alan3354:
Answer by harpazo(655)   (Show Source): You can put this solution on YOUR website!
Five questions?
Where is your effort?

Use the quadratic formula below for all 5 trinomials in the form ax^2+bx+c.

x = [-b+-sqrt{b^2-4ac}]/2a

Show your work.

Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
1. x^2 + 2x -15 = 0
2. 4x^2 + 32x +15 = 0
3. -2x^2 + x +1 = 0
4. 2x^2 +7x + 0
5. -2x^2 +110x + 9 = 0
--------------
I'll do #5
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=12172 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: -0.0816968296006024, 55.0816968296006. Here's your graph:

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#1 - 4 can be factored.

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