True, angle sums are generally equal to (n-2)*180, where n is the number of sides
So solving this you would change the greater than sign to an equal sign 3+4n=31 then you would solve this by subtracting 3 from 31 which gives you 28 so then you have 4n=28 then you divide each side by 4 to get n by itself which gives you n=7 so then you would change back the sign to n>7
the other problem you would do the same thing so 2n-6=18 the first step you would do is add 6 to both sides, 2n=12 then divide both sides by 2 n= 6 then change back the sign n<6 (less than or equal to) make sure to add the dash under the last problem i just couldn’t add it to this on my phone.
Answer:
40 km
Step-by-step explanation:
You have 2 variables: km and minutes/hour
30 minutes turned into 60 minutes(1 hour) by multiplying by 2...
So you need to do the same for km!
20km * 2 = 40km per hour
5x - 5y = 10
x - y = 2 . . . (1)
3x - 2y = 2 . . . (2)
(1) x 3 => 3x - 3y = 6 . . . (3)
(2) - (3) => y = -4
From (1), x - (-4) = 2
x = 2 - 4 = -2
Solution is (-2, -4)
Answer:
c)
Step-by-step explanation:
The definition of an observational study is: one where researchers observe the effect of a risk factor or an intervention but they do not try to change who is exposed to the factor.
In this particular example, the researchers administered a questionnaire to 391 twelve-year-old and concluded that the body mass index of the adolescents who had a supply of sugary snacks in their bedroom was significantly higher than that of the adolescents who did not have a supply of sugary snacks in their bedroom.
This is not an observational study because the researchers actually administered a questionnaire and analyzed the results. To be an observational study the individuals would have been observed without any intervention (the questionnaire could have had an effect on the adolescents changing their habits)
