Question

Solve 3x^2-x=10

A:x=2 and x=-15
B:x=-5 and x=2/3
C:x=-5/3 and x=2
D:x=-3 and x=10

Answer 1

C

Explanation:

∆=b^2-4a*c=1-4*3*(-10)=121>0 có 2x

x1=-b+sprt∆/2a=1+sprt121/2*3=2

x2=-b-sprt∆/2a=1-sprt121/2*3=-5/3