SOLUTION: Solve using the quadratic equation {{{3x^2+2.5x=12.5}}}

Algebra.Com
Question 857661: Solve using the quadratic equation
Answer by richwmiller(17219)   (Show Source): You can put this solution on YOUR website!
3x^2+2.5x-12.5=0
Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:


Starting with the general quadratic





the general solution using the quadratic equation is:







So lets solve ( notice , , and )





Plug in a=6, b=5, and c=-25




Square 5 to get 25




Multiply to get




Combine like terms in the radicand (everything under the square root)




Simplify the square root (note: If you need help with simplifying the square root, check out this solver)




Multiply 2 and 6 to get 12


So now the expression breaks down into two parts


or


Lets look at the first part:





Add the terms in the numerator

Divide


So one answer is






Now lets look at the second part:





Subtract the terms in the numerator

Divide


So another answer is




So our solutions are:

or


Solved by pluggable solver: SOLVE quadratic equation with variable
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=156.25 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 1.66666666666667, -2.5. Here's your graph:


RELATED QUESTIONS

Please help solve this quadratic equation using the quadratic forumla. {{{ -3x^2 - 5x... (answered by mananth)
Solve using the quadratic equation: x^2 - 3x - 23 = 5 3x^2 - 2x = 15x -... (answered by checkley71)
solve(3x)^2-12√(3x)+27=0 using the quadratic equation. explain the steps... (answered by stanbon)
1) Solve the quadratic equations by factoring: 5x² = 125 2) Solve the quadratic... (answered by checkley71)
Solve each equation using the quadratic formula. 1.x^2+10=-25... (answered by Alan3354)
solve equation using quadratic formula... (answered by checkley77)
solve each equation using the quadratic formula: 1.) 4x^2+x-5=0 2.) 2x^2-5x+2=0... (answered by mananth)
Solve using the quadratic formula.... (answered by Alan3354,jim_thompson5910)
solve using the quadratic formula.... (answered by jim_thompson5910)