SOLUTION: How would you solve this quadratic equation 5x squared - 8x +3=0
Algebra.Com
Question 2153: How would you solve this quadratic equation 5x squared - 8x +3=0
Answer by longjonsilver(2297) (Show Source): You can put this solution on YOUR website!
you would hope it factorised firstly. If you could not see the factors, you would have to resort to "completing the square" or the "number crunching" version of this...the Quadratic formula.
For factorising...always the simplest solution and "good fun". Well, OK, not good fun, but certainly "enjoyable". Well, OK, not enjoyable...lol i digress with some English humour, sorry :-D
Factorising...we want 2 things multiplied together...()()=0. These will both have an x term and a pure number term, in general (x+a)(x+b), which expands to give x^2 + (a+b)x + ab. Your equation is lightly more complicated in that you have a 5 factor too!
so...2 "x" terms that give 5x^2?...take the obvious...5x and x. Voila. First guess done, so we have (5x)(x)=0
Now for the a and b terms!. Look at the general equation...the a and b multiply to give ab and then also add to give the coefficient of the x term. So basic numbers for you. As you Americans would say...4th grade stuff (or whatever)...
Your equation is more tricky in one sense, but because of that, it is easier n another sense...
which 2 number multiply to give +3
and also add together to give -8.
Well?
the answer we need is ONLY 1x3 works easily for us, so let's hope these are the answers!!!. This is approach i use to this day, so do not feel it is a cop-out to work like this.
So either (5x-1)(x-3) or (5x-3)(x-1) is the answer, i hope.
The first answer when multiplied out will give the following terms...-15x and -3x..no way is this -8x, so WRONG WRONG WRONG!!!!
Second answer? well this will give -5x and -3x which is -8x. YIPPPEEEEE, the answer...
(5x-3)(x-1)=0
hence 5x-3=0 OR x-1=0
so
x=3/5, x=1
jon
RELATED QUESTIONS
how would you solve this quadratic equation y squared plus 3y plus... (answered by College Student,dabanfield)
How do you solve this quadratic equation???
x squared... (answered by Greenfinch,Theo)
How do you solve this quadratic equation... (answered by Alan3354)
How do you solve 5x squared plus 16x minus 84 equals 0 using the quadratic equation... (answered by KMST)
how do you solve this equation? (x-7x)squared=5=0 its a quadratic equation(completing a... (answered by ikdeep)
how would you solve for 8x squared – 12x =... (answered by jim_thompson5910)
Hi everyone, I need to know how to solve this equation 8x^6+7x^3-1=0 by using the... (answered by xcentaur)
How would you find the sum and product of the root of this quadratic equation?
1.{{{... (answered by ichudov,Yuchengco)
how do you solve this system of equations
x squared + y squared = 9... (answered by funmath)