x 2 − 13 x = − 30 is equivalent to:

Answer 1

x^2 -13x +30 = 0

(x-10)(x-3) = 0

x = 3 or 10

9-39+30 = 0

100-130+30 = 0

if you can't factor (which is largely trial and error) use the quadratic formula

x=-b/2a +/-(1/2a)sqr(b^2-4ac) with a=1, b=-13, c=30

x = 13/2 +/-.5sqr(169-120)

= 6.5 +/-.5sqr49

= 6.5 +/-.5(7)

=6.5+3.5 or 6.5-3.5

= 10 or 3