Option C is the right way to solve the equation.
Answer: Jennifer didn't randomly assign participants to the control and experimental group.
Step-by-step explanation: In the scenario discussed above, Jennifer failed to perform a random assignment of the participants who took part in the survey, that is the experimental group, those who receive the treatment and the control group, those who don't. Random assignment is required in other to address the issue of bias in our experiment. She was supposed to perform a random assignment of the participants to the two groups instead of asking them to make a choice.
Answer:
y=30x+50 and y=40
Step-by-step explanation:
To find the number of zeros in the quadratic equation we factorize it as follows:
f(x)=x²+6x+18
solving using completing square methods we obtain:
x^2+6x=-18
c=(b/2a)^2=9
thus
x²+6x+9=-18+8
x²+6x+9=-9
(x+3)²=-9
hence
x=-3+/-3i
the roots are:
x=-3+3i or x=-3-3i