quadratic formula?

Question

3x^2+7x+13=13 using the quadratic formula i dont understand this type of problem

Answer 1

the standard form of a quadratic equation is ax^2+bx+c=0
the formula is used for finding the roots of theequation as follows
x1=[-b+(b^2-4ac)^1/2]/2a :x2=[-b-(b^2-4ac)^1/2]/2a
here a=3,b=7 and c=0 after we rewrite it as 3x^2+7x+13-13=0
substituting the values x1=(-7+7)/6=>0 and x2=(-7-7)/6=-7/3

another easier method will be as follows 3x^2+7x=0,taking out
x as a commomn factora nd using the dietributive property
x(3x+7)=0. if a product is zero each factor must be zero.
applying this rule either x=0 or 3x+7=0 which gives x=-7/3

Answer 2

The object of this sort of question is to determine what x is worth. First we must get the formula in the form of ax^2+bx+c=0, so subtract 13 from either side of the equation and you'll end up with 3x^2+7x+0=0

THe quadratic formula is x= -b+(b^2-4ac)^(1/2)/2a or x= -b- b^2-4ac)^(1/2)/2a (AKA negative b plus or minus the square root of b squared minus 4ac all over 2a).

In this case, a=3, b=7 and c=0

Hope this helps.

Answer 3

hey dude quadratic formula is used to calculate roots of a quadratic equation.
for doing this u first find values for the variables a,b and c from the equation of the form
ax^2+bx+c=0
for example in ur equaton
a=3 b=7 c=0
now since a quadratic equation has two roots
u will calculate
root 1= -b+square root of b^2-4ac/2a
and
root2= -b-square root of b^2-4ac/2a
whr a=3 b=7 c=0 for ur question both the roots can be obtained
and ans=root 1,root 2.

warning: the second answer by phenomkiller is also right but it is not using quadratic formula
it is using factorization method....

Answer 4

quadratic formula is -b + (sq root of) b^2 - 4ac/2a.

3 is a (it's got an x squared in it above).
7 is b (it's got an x in it above).
13 is c (it's an integer, or a plan ol' number).


so basically... put the a value (3x^2) where it says a in the quad. formula, b into b, c into c, etc.

then solve.




but please don't use this site to cheat on your homework (or whatever it is you're doing)--it's a waste of time, and you'd have better luck just talking to your teacher! he/she will help you out, no doubts. be mature about it, and good luck. ;)

Answer 5

3x^2+7x+13=13
3x^2+7x+13-13=0
3x^2+7x=0
factorize to get x
x(3x+7) so,
x=0 & 3x+7=0
3x= -7
x= -7/3