Q:

14. Solve: 3x² + 5x – 12 = 0B. 4-3C. 8, - 18​

Accepted Solution

A:
Answer:bStep-by-step explanation:The equation: 3 x 2 − 5 x − 12 = 0 is in the form: a x 2 + b x + c = 0 with  a = 3 ,  b = − 5 ,  c = − 12 The roots are given by the quadratic formula: x = − b ± √ b 2 − 4 a c 2 a x = 5 ± √ ( − 5 ) 2 − 4 ( 3 ) ( − 12 ) 2 ( 3 ) x = 5 ± √ 25 + 144 6 x = 5 ± √ 169 6 x = 5 ± 13 6 That is: x = 5 + 13 6 = 18 6 = 3   or    x = 5 − 13 6 = − 8 6 = − 4 3