Me need help its hard

The polynomial function of least degree with a leading coefficient of 1 is: f(x) = x3 + ax2 + bx + c

What is the solution set of the quadratic inequality x2- 5< 0? o {xl-55x55{x- 155x55){xl -55x5 15){x1 - 15 sx5/5)

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.