SOLUTION: solve each equation using the quadratic formula: 1.) 4x^2+x-5=0 2.) 2x^2-5x+2=0 3.)3x^2+7=-6x 4.) 7x^2-x-12=0

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: solve each equation using the quadratic formula: 1.) 4x^2+x-5=0 2.) 2x^2-5x+2=0 3.)3x^2+7=-6x 4.) 7x^2-x-12=0      Log On


   

Question 396016: solve each equation using the quadratic formula:
1.) 4x^2+x-5=0
2.) 2x^2-5x+2=0
3.)3x^2+7=-6x
4.) 7x^2-x-12=0
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
1.) 4x^2+x-5=0
I will solve one with detailed steps. Rest i am sure you can walk through

Find the roots of the equation by quadratic formula
a= 4 , b = 1 , c = -5
b^2-4ac= 1*1 - (4*4*(-5))= 81 .
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29

x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=+%28-%281%29%2Bsqrt%2881%29%29%2F%282%2A4%29
x1=%28-1%2Bsqrt%2881%29%29%2F8
x1=1
...
x2=%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x2=%28-1-sqrt%2881%29%29%2F8
x2= -1.25
1, -1.25 are the roots of the equation.


2.) 2x^2-5x+2=0
a=2,b=-5,c=2
3.)3x^2+7=-6x
4.) 7x^2-x-12=0