Solve the equation by the method of your choice?

Question

(x-10)(x-2)= -20

I am getting as far as

x^2 - 12x +20 = -20

x^2 -12x + 40 = 0

Answer 1

OK

If you can't factor use the quadratic equations:

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

So in your equation ax^2 + bx + c =0

12 +- sqrt (144 - 4(1)(40)) / 2
12 +- sqrt (144-160) /2
12 +- sqrt (-16) /2
12 +- 4i /2
6 +- 2i
So the answers are

(6 + 2i) or (6 - 2i)

Check

(6+2i)^2 - 12(6+2i) +40 =0 ??
36 +24i -4 - 72 -24i +40 = 0??
-40 + 40 = 0 ??
0=0 YES!!

Hope that helps.

Answer 2

Use the quadratic formula (see link below).

The answer I get is x = 6+2i, 6-2i, where i is sqrt(-1).

Answer 3

x = (12 +/- Sqrt(144-4*40)) / 2

since sqrt(-16) is negative, there is no real root

or x = 6 + 2i or 6 - 2i

Answer 4

you will need imaginary numbers for the solution i = sqrt(-1)

The solution would be x=6-2i and x = 6+2i.

Answer 5

if you graph it you will find that the equation has no zeros therefore there are no real roots you can find the imaginary roots by using the quadratic formula

Answer 6

6+2i
or
6-2i

if you arent using i yet, then there is no rational solution.

Answer 7

No real solutions