Question

X x X -4X -13=0 HELP PLEASE

Answer 1

Well:
x*x-4x-13=0

multiply the x's
x^2-4x-13=0

now we need to factor, it doesn't look like there will be a simple answer so we will need to use the quadratic formula:
x=-b\[x=(-b \pm \sqrt{b^2 - 4ac})/2a\]

in your case:
a=1, b=-4, and c=-13

so
x= \[(4 \pm \sqrt{16-4*1*(-13)})/2*1\]

now we'll just continue to simplify
x= \[(4 \pm \sqrt{16+52})/2\]

x= \[(4 \pm \sqrt{68})/2\]

x= \[(4 \pm \sqrt{17*4})/2\]

x=\[(4 \pm 2\sqrt{17})/2\]

x=\[(2 \pm \sqrt{17})\]

and that is your final answer:
x= \[(2 + \sqrt{17})\], \[(2 - \sqrt{17})\]

let me know if you have more questions