what is the value of x??
(2x+14)(x+14)=952

Question

what is the value of x?? 
(2x+14)(x+14)=952

turingtest · Answer

FOIL:
2x^2+2(14x)+14x+196=2x^2+42x+196=952
2x^2+42x-756=x^2+21x-378=0
can you use the quadratic formula from here? 'cause I don't want to...

turingtest · Answer

$$x=(-b \pm \sqrt{b^2-4ac})/2a$$

unklerhaukus · Answer

(2x-14)(x-14)=9522
2(x-7)(x-14)=9522
(x-7)(x-14)=4761

turingtest · Answer

where $$ax^2+bx+c=0$$ is the form
so plug in
a=1
b=21
c=-378
into the formula above and simplify

anonymous · Answer

wow you guys are math wizs:)

turingtest · Answer

it's just algebra :)

turingtest · Answer

@ unk
dude i think you messed up and forgot about the -4761, check your answer.

turingtest · Answer

a=1
b=21
c=-378
$$x=(-21 \pm \sqrt{21^2-4(1)(-378)})/2=(-21 \pm \sqrt{1953)}/2$$

turingtest · Answer

$$=(-21 \pm 3\sqrt{217})/2=(3/2)(-7 \pm \sqrt{217)}$$

turingtest · Answer

so$$x=\left\{ (3/2)(-7-\sqrt{217},(3/2)(-7+\sqrt{217)} \right\}$$ is what I got

unklerhaukus · Answer

whoops

turingtest · Answer

am I right? or did I mess up too? this one was long and annoying :(

unklerhaukus · Answer

im gonna try on on paper instead of in my head...

turingtest · Answer

@ alexandraox3 I think my answer is the right one.