minus 14 from both sides
x²-4x-14=0
use quadratic formula because we cant factor
for
ax²+bx+c=0
[tex]x= \frac{-b+/- \sqrt{b^2-4ac} }{2a} [/tex]
so
1x²-4x-14=0
a=1
b=-4
c=-14
[tex]x= \frac{-(-4)+/- \sqrt{(-4)^2-4(1)(-14)} }{2(1)} [/tex]
[tex]x= \frac{4+/- \sqrt{16+56} }{2} [/tex]
[tex]x= \frac{4+/- \sqrt{72} }{2} [/tex]
[tex]x= \frac{4+/- 6\sqrt{2} }{2} [/tex]
[tex]x= 2+/- 3\sqrt{2} [/tex]
the solutions are
x=2+√3 and
x=2-√3
