Question

K^2+8k-9=0 can you help me solve with showing work

Answer 1

Using the PSN method:

P = -9
S = 8
So N = 9,-1

Using 9 and -1 in the original equation gives:

$k^2+9k-k-9=0 \\k(k+9)-1(k+9)=0 \\(k-1)(k+9) \\\\k=1,-9$

Answer 2

K² + 8k - 9 = 0
k = -8 +/- √(8² - 4(10)(-9))
                   2(1)
k = -8 +/- √(64 + 360)
                   2
k = -8 +/- √(424)
               2
k = -8 +/- 20.59126028
                     2
k = -8 + 20.59126028    k = -8 - 20.59126028
                    2                                    2
k = 12.5912608             k = -20.5912608
              2                                     2
k = 6.2956304                k = -10.2956304