Answer:
x = (5,3)
Step-by-step explanation:
the quadratic formula is x =( -b±√(b^2-4ac))/2a
to solve for x, a=1, b=-8,c=15
x =( -(-8)±√((-8)^2-4*1*15))/2(1)
x=8 ± √(64-60))/2(1)
x=(8 ± √(4)) / 2
x=(8 ± 2) / 2
solve with '+'
x=(8 + 2) / 2 = 10/5 = 5
solve with '-'
x=(8 - 2) / 2 = 6/2 = 3
x = (5,3)
(0,1) is the y intercept because the point (0,1) lies on the y axis.
4. is correct
5. A is correct
6. B is correct
Since only 30% of the teachers taught for one year, the remaining percentage of the teachers had taught for more than a year, or 70%.
70%=0.7
80(0.7)=56
56 teachers had taught for more than a year.
