X3-7x=6x-12
x3-7x-6x+12=0
x3-13x+12=0
(x-1)(x2+x-12)=0
Calculate delta of the second bracket:
delta = 1+4*12=49
sqrt(delta)=sqrt(49)=7
x_1=(-1-7)/2=-4
x_2=(-1+7)/2=3
(x-1)(x+4)(x-3)=0
Answear:
Roots: x=1, x=-4, x=3.
Answer:
A. principal interviewed the 25 students who scored highest on a reading test.
D. For a report on the exercise habits of adults, Sergio talked to 30 adults at a local fitness center.
E. Josh asked the first 25 people he met at the dog park if they preferred dogs or cats.
Step-by-step explanation:
Biased means if the selection of every unit does not have an equal chance of being selected in a sample.
The sample is said to be good if choosing the unit is unbiased. The sample is said to be unbiased if the selection of each unit is independent.
Option A is an example of data selected in a biased way because principal chose only those student who scored the highest marks on reading test.
Options B and C are unbiased as here a selection of each number and name of the student has an equal chance of being selected.
Option D is biased because Sergio talked adults at a local fitness center where people go for maintaining their health. So, there is a chance of the selection of fitted adults more than unfitted adults.
Option E is biased because Josh met people at the dog park where dog lovers are more than a cat lover.
Answer:
Subtract 5 from both sides would be the first step for solving
Step-by-step explanation:
