Tentukan akar akar dari persamaan kuadrat 3x²+7x-40=0 dengan rumus abc
Jawaban:
3x² + 7x – 40 = 0
-b ± √-b² – 4ac/2a
= -7 ± √ -7² + 4(3)(40)/2(3)
= -7 ± √49 + 480/6
= -7 ± √529/6
= -7 ± 23/6
x1 = -7 + 23/6
= -56/6 + 23/6
= -33/6
= -11/2
x2 = -7 – 23/6
= -56/6 – 23/6
= -79/6