Question

15x^2-28=x find the rood by quadratic formula​

Answer 1

Answer:

x =(1+√1681)/30=(1+41)/30= 1.400

or:

x =(1-√1681)/30=(1-41)/30= -1.333

Answer 2

-21

20

Step-by-step explanation:

Quadratic formula is x = (-b ± √D)/2a

Quadratic equation is 15x² - x - 28 =0

D = b² - 4ac = 1 - 4×15×-28 = 1+1680 = 1681

so (-b ± √D)/2a = (1 ± √1681)/-2 = (1 ± 41)/-2

So Case 1:- (1+ 41)/-2 = -21

Case 2:- (1-41)/-2 = 20