Sagot :
[tex]a+b=28 \\\\\ a=2b+4 \\\\ 2b+4+b=28\\\\ 3b=28-4\\\\3b=24 \\\\ \boxed{b=\frac{24}{3}=8} \\\\a=2*8+4\\\\a=16+4 \\\\ \boxed{a=20}[/tex]
Answer:
Let x be the first group of students in a class and y be the second group of students in the class.
As per the statement:
As, the teacher separated her class of twenty-eight students in two groups.
⇒ x+y = 28 ......[1]
Also, one group has 4 more than twice as many as the other group.
⇒ x = 4 + 2y ......[2]
Now, substitute the equation [2] in [1]; we have
[tex]4+2y+y = 28[/tex]
Combine like terms;
4 + 3y = 28
Subtract 4 from both sides we get;
[tex]4+3y-4 = 28-4[/tex]
Simplify:
3y = 24
Divide by 3 to both sides we get;
[tex]\frac{3y}{3} = \frac{24}{3}[/tex]
Simplify:
y = 8
Now, substitute the value of y in equation [2] to solve for x;
[tex]x = 4 + 2(8) = 4 +16 = 20[/tex]
or
x = 20
therefore, the number of students in each group are 20 and 8.