On the algebra test the number of students who got a grade a was three more than twice the number of students who got lower grades. how many a's were there if total number of students in the algebra class is 24?

X= # students who got lower grades
2x+3= # students with grade A

STEP 1:
Add the two sets above equal to 24.

x + (2x + 3)= 24
combine like terms

3x + 3= 24
subtract 3 from both sides

3x= 21
divide both sides by 3

x= 7 (# students lower than A)

STEP 2:
substitute x value from step 1 to find # grade A students

=2x + 3
=2(7) + 3
=14 + 3
=17 (# grade A students)

CHECK:
x + (2x + 3)= 24
7 + 2(7) + 3= 24
7 + 14 + 3= 24
24= 24

ANSWER: There were 17 students with grade A.

Hope this helps! :)