What is y = x^2 + 2x - 8 factored?

Question

how to factor when there is 2 variables

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Answer 1 · 2018-05-02T21:38:19

#x^2+2x-8=0#

#x=(-2+-sqrt(2^2-4*1*(-8)))/(2*1)=(-2+-sqrt(36))/(2)=(-2+-6)/(2)#

#x=(-2-6)/(2)=(-8)/(2)=-4#

#x=(-2+6)/(2)=(4)/(2)=2#

#y=(x+4)(x-2)#

If you want to factorize #x^2+2x-8#.

Choosing the quadratic equation to factorize.

#x^2+2x-8=0#

#x=(-b+-sqrt(b^2-4ac))/(2a)#

Where #a=1, b=2# and #c=-8#

#x=(-2+-sqrt(2^2-4*1*(-8)))/(2*1)=(-2+-sqrt(36))/(2)=(-2+-6)/(2)#

Which will give,
#x=(-2-6)/(2)=(-8)/(2)=-4#
And,
#x=(-2+6)/(2)=(4)/(2)=2#

Your factorized form will then be,

#(x+4)(x-2)#