SOLUTION: Use the quadratic formula to solve. 2x squared - 5x = 3

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Use the quadratic formula to solve. 2x squared - 5x = 3      Log On


   



Question 122123: Use the quadratic formula to solve.
2x squared - 5x = 3

Found 2 solutions by madhan_math, praseenakos@yahoo.com:
Answer by madhan_math(34) About Me  (Show Source):
You can put this solution on YOUR website!
Given equation is 2x^2-5x=3
2x^2-5x-3=0
Now the coefficient of x^2 and constant multiplying, we get
-6.
Then, we find two numbers that numbers will be added we get -5(the coefficient of x)and multiply that numbers will become -6.
Therefore, that numbers are -6, 1
Now the given equation becomes 2x^2-6x+x-3=0.
(We take common number from first two variables.)
i.e., 2x(x-3) + 1(x-3)=0
i.e., (2x+1)=0,(x-3)=0 are the factors of the given eqn.
Hence x=-1/2 and x=3.
(OR)
The problem also solve by using the formula
http://www.algebra.com/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29&x=0003
In this equation a=2, b=-5, c=-3 and substitute these values in that formulae we will get x=-1/2 and x=3.

Answer by praseenakos@yahoo.com(507) About Me  (Show Source):
You can put this solution on YOUR website!
Question:
Use the quadratic formula to solve.
2%28x%29%5E2+-+5x+=+3

Answer:
The equation can be written as,
2%28x%29%5E2+-+5x+-+3=+0


Quadratic formula is,
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

Here a = 2, b = -5 and c = -3

==> x+=+%28-%28-5%29+%2B-+sqrt%28+%28-5%29%5E2-4%2A2%2A%28-3%29%29%29%2F%282%2A2%29+


==> x+=+%285+%2B-+sqrt%28+25%2B24%29%29%2F4+


==> x+=+%285+%2B-+sqrt%28+49%29%29%2F4+


==> x+=+%285+%2B-+7%29%2F4+


==> x+=+%285%2B7%29%2F4 or x+=+%285-7%29%2F4



==> x+=+%2812%29%2F4 or x+=+%28-2%29%2F4




==> x+=+3 or x+=+-1%2F2 which is the required solution.


Hope you found the explanation useful.


Regards.

Praseena.