When a quadratic equation ax^2+bx+c has a double root, the discriminant,
D=b^2-4ac=0
Here
a=2,
b=b,
c=18
and
D=b^2-4ac=b^2-4*2*18=0
solve for b
b^2-144=0
=> b= ± sqrt(144)= ± 12
So in order that the given equation has double roots, the possible values of b are ± 12.
Good luck i cant read it tho if i could read it i would help sorry
(d-2.8)/0.2=-14
d-2.8=-14*0.2
d-2.8=-2.8
d=-2.8+2.8
d=0
