There is one positive solution (x=2.87)
The approximate value of the greatest solution is 2.87
To do a quadratic equation you have the quadratic formula of: ( -b+/- sqrt b^2-4ac)/2a
In order to use it, you need your equation to equal zero so subtract 21 from both sides:
x2+2x-14
Now you can define a, b, and c
a=1, b=2, c=-14
Now plug them into the equation!
-(2)+ sqrt (2)^2-4(1)(-14)/ 2(1) = 2.87298
Make sure to do subtraction as well! ( plus OR minus)
-2- sqrt 2(2)^2-4(1)(-14)/2(1) = -4.87298
You can double check the answers by plugging them back into the original equation :)
Looks like there’s only one POSITIVE solution, x=2.87
This is also the greatest solution, so x=2.87 :D
