solve the following quadratic equations by factoring: 2x^2-3x=x^2+18
First of all we need to bring it into the standard form of quadratic equation and compare to find a,b and c The standard form is, \[ax^2+bx+c=0\] Then we need to use the quad formula which is, \[x=\frac{ -b \pm \sqrt{b^2-4ac} }{ 2a }\] The other methods we can use here are as follows: 1)Breaking the middle term 2)Completing the whole square.
but my problem is exactly where to start
X(X-3) + 6(X-3) = 0
X=3
Um,The first step is to bring it into standard form, \[ax^2+bx+c=0\]
so we would have............
2x^2-3x=x^2+18 Subtract both sides by (x^2+18)
Sorry is X(X+3) - 6(X+3) = 0 X= +/- 3
\[x^2-3x-18=0\]
Yeah right :)
so now im stuck again........hmmph
Can you use the quadratic formula ?
we divide by x ???
Think of two numbers when we add or subtract we get -3 and when we multiply we get -18
i know its 6 but what would the work looklike
What do you mean by its 6 ?
I said two numbers.
-3 and 6
Ok so here it is, \[x^2-6x+3x-18=0\]
Now take common from first two terms and then last two terms.
\[so -6x+3x would be together on 1 term\]
No like, x(x-6) + 3 (x-6)=0
Either, x-6=0 Or, x+3=0
Now solve and get the values of x :)
thank you so much for the help
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