I would reduce it first to
x^2 + x - 12 = 0
then:
a = 1, b = 1, c = -12
so...
x = (-1 ± √(1 - 4(1)(-12))/2
= (-1 ± √49)/2
= (-1 ± 7)/2
= 3 or -4
how do I solve 5x^2+5x-60=0 using the quadratic formula?
2 answers
well first divide both sides by 5
1 x^2 + 1 x - 12 = 0
x = [ -1 +/- sqrt( 1 -4(1)(-12) ] / 2
x = [ -1 +/- sqrt(49)] /2
x = [ -1 +/- 7 ]/2
x = 3 or x = -4
CHECK
5*9 + 5*3 - 60 = ?
45 +15 - 60 = 0 sure enough
1 x^2 + 1 x - 12 = 0
x = [ -1 +/- sqrt( 1 -4(1)(-12) ] / 2
x = [ -1 +/- sqrt(49)] /2
x = [ -1 +/- 7 ]/2
x = 3 or x = -4
CHECK
5*9 + 5*3 - 60 = ?
45 +15 - 60 = 0 sure enough