# Thread: did this equation b+3+b=68

1. ## did this equation b+3+b=68

.....for this problem and I don't kno what am I doing wrong. I did it jus like Mark showed me >.>

Mr. Alfaro has 3 times as many Pre-Algebra students than Beginning Algebra students. If Mr. Alfaro has a total of 72 students, find the number of students in each course.

a) Write the equation you would use to solve this problem, using ${b}$ as the number of Beginning Algebra students. ___________

b) After solving the equation, how many Beginning Algebra students does Mr. Alfaro have? __________

c) After solving the equation, how many Pre-Algebra students does Mr. Alfaro have? __________

2. ## Re: did this equation b+3+b=68

What two equations do you have from the information given?

3. ## Re: did this equation b+3+b=68

I got 3+b+b=72
then i subtract -3 from both side
got b+b= 69/2
b=34.5 then I did 3+34.5 =37.7

so I got B= 34.5 and P =37.5 both equal to 72

4. ## Re: did this equation b+3+b=68

well now I'm working with different numbers but same concept.

5. ## Re: did this equation b+3+b=68

Let $p$ be the number pf Pre-Algebra students,a dn $b$ be the number of Beginning Algebra students.

From the statement "Mr. Alfaro has 3 times as many Pre-Algebra students than Beginning Algebra students" we may write:

$p=3b$

You see this is a bit different from the previous problems because we are give that one quantity is a certain multiple of the other rather than being told one is a certain amount more or less than the other.

From the statement "Mr. Alfaro has a total of 72 students" we may write:

$p+b=72$

Now, what should you do next?

6. ## Re: did this equation b+3+b=68

but formy first equation I did... b+3+b=68
-3 -3
_____________
b + b = 65
2b = 65
b=32.5 ; /

7. ## Re: did this equation b+3+b=68

Originally Posted by MarkFL2
Let $p$ be the number pf Pre-Algebra students,a dn $b$ be the number of Beginning Algebra students.

From the statement "Mr. Alfaro has 3 times as many Pre-Algebra students than Beginning Algebra students" we may write:

$p=3b$

You see this is a bit different from the previous problems because we are give that one quantity is a certain multiple of the other rather than being told one is a certain amount more or less than the other.

From the statement "Mr. Alfaro has a total of 72 students" we may write:

$p+b=72$

Now, what should you do next?

3b+b=72

8. ## Re: did this equation b+3+b=68

Yes, so what do you find when you solve for b?

9. ## Re: did this equation b+3+b=68

Originally Posted by MarkFL2
Yes, so what do you find when you solve for b?
b=18

10. ## Re: did this equation b+3+b=68

Correct, so what must p be?

11. ## Re: did this equation b+3+b=68

Originally Posted by MarkFL2
Correct, so what must p be?

P=54

12. ## Re: did this equation b+3+b=68

Yes. Good work!