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HELP Quadratic formula NOOOOOOOO
This topic has expert replies
There are two methods for solving these
1. completing the square
2. Using formula (-b+-sqrt(b-4ac))/2a
i prefer to use 2
so first thing is ti het the equation on standard form (ax^2+bx+c=0)
in your case 4x^2-9x=0
where
a=4
b=9
c=0
answers follows
1. completing the square
2. Using formula (-b+-sqrt(b-4ac))/2a
i prefer to use 2
so first thing is ti het the equation on standard form (ax^2+bx+c=0)
in your case 4x^2-9x=0
where
a=4
b=9
c=0
answers follows
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Don't forget that it's b^2 - 4ac under the root, not b - 4ac. Fortunately we don't need to use the quadratic formula on the GMAT, as long as we know how to factor. So, if you need to solve for x in the question above:dimonya wrote:There are two methods for solving these
1. completing the square
2. Using formula (-b+-sqrt(b-4ac))/2a
i prefer to use 2
4x^2 = 9x
4x^2 - 9x = 0
x(4x - 9) = 0
The product of two things is zero --> one of them must be zero:
x = 0
or
4x - 9 = 0 ---> x = 9/4
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