Answer:
3 groups of 5
Explanation:
if x is the number of groups of four, and y is the number of groups of five, then 4x +5y =39 (four students per group of four times the # of groups of four, and 5 students per group times the # of groups of five, which should equal the total amount of students, 39). also, x+y=9. (number of each type of group = 9 groups total).
then, use these two equations and solve for y, by "canceling out" x. there are many ways to do this, but i'm going to use subtraction.
4x-5y=39
x+y=9
you want to change the equation
x+y=9
into
4x+4y=36
by multiplying the whole equation by four. because in order to cancel out the x, you need it to equal zero. in the first equation, its 4x.
so its now
4x-5y =39 MINUS
4x+4y=36
___________
y=3
you can check your work because the remaining 6 groups of four (24 total students) plus the 3 groups of five (15 total students) adds up to equal 36
The answer is: directional research hypothesis
directional research hypothesis is a form of prediction that initiated in order to guess whether two variables would experience some sort of positive or negative changes. In the example above, boys and girls are the variables and whether they agree or disagree with school rules are the changes.