the teacher separated her class of twenty-eight student into two group. one group has 4 more than twice as many students as the other group. how many students are in each group?
There are 20 students in one group and 8 students in the other. To represent this as an equation, x + y = 28, where y = 2x + 4. Therefore, x + 2x + 4 = 28. 3x + 4 = 28. 3x = 24. x = 24/3. x = 8. Put the x value into the y equation and it gives you 20.
For this case, the first thing we must do is define variables:
x: students of group 1
y: students of group 2
We now write the system of equations that models the problem:
\(x + y = 28
y = 2x + 4
\)
Solving the system by substitution we have:
\(x + (2x + 4) = 28
3x + 4 = 28
3x = 28-4
\)
\(3x = 24
\)
\(x = \frac{24}{3}
x = 8
\)
Then, the value of y is given by:
\(y = 2 (8) +4
y = 16 + 4
y = 20
\)
Answer:
8 students of group 1
20 students of group 2