Answer:
x = -2 ±sqrt(7)
Step-by-step explanation:
3x^2 +12 x = 9
Divide each side by 3
3x^2 /3 +12x/3 = 9/3
x^2 +4x = 3
Take the coefficient of x
4
Divide by 2
4/2 =2
Square it
2^2 =4
Add it to each side
x^2 +4x+4 = 3+4
x^2 +4x+4 = 7
(x+2)^2 = 7
Take the square root of each side
x+2 = ±sqrt(7)
Subtract 2 from each side
x+2-2 = -2 ±sqrt(7)
x = -2 ±sqrt(7)
Answer:
B
Step-by-step explanation:
The retrospective or historic cohort story, is a longitudinal cohort story that considers a particular set of individuals that share the same exposure factor to ascertain its influence in the developments of an occurrence, which are compared with the other set or cohort which were not exposed to the same factors.
Retrospective studies have existed about the same time as prospective studies, hence their names.
Isolate the variable by dividing each side by factors that do not contain the variable.
2x=2x-4y+16
2x-16=2x-4y
-4y would have to equal -16
Therefore Y=4
