Question

Solve. x^2 – 10x = –13
5 ± 2 sqrt 3
5 ± sqrt 38
5 ± 2 sqrt 2
5 ± 3 sqrt 2

Answer 1

first move everything to one side
x^2 - 10x + 13
use the quadratic formula.
(-b +/- sqrt(b^2 + 2ab))/2a

Answer 2

oops i mean - 4ac for the quadratic. you'll get
(-10 +/- sqrt(100-52))/2
so -5 +/- sqrt (12)
someone correct me if i'm wrong please.

Answer 3

\[\frac{10\pm\sqrt{10^2-4(1)(13)}}{2(1)}\]
\[\frac{10\pm\sqrt{100-52}}{2}\]
\[\frac{10\pm\sqrt{48}}{2}\]
\[\frac{10\pm\sqrt{3(16)}}{2}\]
\[\frac{10\pm4\sqrt{3}}{2}=5\pm2\sqrt{3}\]

Answer 4

The quadratic setup was right. You had until you started reducing.

Answer 5

you have the answer but i would like to point out that if you see the middle term is even and you 'complete the square' you can avoid a lot of reducing

Answer 6

\[x^2-10x-13\]
\[(x-5)^2=-13+25=12\]
\[x-5=\pm2\sqrt{3}\] etc

Answer 7

formula forces a denominator on you (2a) which is unnecessary if the coefficient of the "middle term" is even (assuming it is monic)