Question 1

I really don't understand problem 1, could someone explain??
Why isn't it 0?

Accepted Answer

I'm going to assume you mean problem 1 in "let's practice" rather than the 1st problem in the video or just below the video.

Problem 1 in practice is:  (3/2)y-3+(5/3)z given the values of y=4 and z=3
Substitute the vales for the variables: 
(3/2)(4/1)-3+(5/3)(3/1)
Follow PEMDAS rules.  Multiply first.
(3/2)(4/1)=12/2=6
(5/3)(3/1)=15/3=5
So, the expression is now: 6-3+5
Now, add and subtract from left to right.
6-3+5 = 3+5 = 8

The answer is 8.  Why do you think it should be 0?
Hope this helps.

Question 2

why do we do this?

Accepted Answer

You do this so that you can figure out how much of something there is when you have an unknown amount that can change.

Question 3

Why is the answer to the second question 11? If I follow the order of operations shouldn't the answer be 5? Do addition first.. so 5 + 3 = 8.. then subtraction 13 - 8 = 5..

Accepted Answer

You aren't quite following order of operations.  In PEMDAS, there are 4 steps, not 6.
P = Parentheses: Do any work inside first
E = Exponents:  Do any exponents or radicals next
MD = Multiply & Divide:  These are one step.  You need to work them from left to right
AS = Add & Subtract:  These are one step.  Again, you need to work them from left to right
So, when applied to the 2nd problem: 13-5+3
You go left to right: 13-5=8
Then 8+3=11

Hope this helps.

Question 4

Wait, so, the first practice question has 3 over 2, isn't that an improper fraction? Am I supposed to treat it as an improper fraction and divide 3 into 2? Or, do I treat it as a normal fraction and try and figure out the problem? When I try to divide 3 into 2, i get 0.666... and so on. Thanks!

Accepted Answer

It's good that you saw that the answer 0.666... does not make good sense for the improper fraction 3 over 2.  This should tell you that dividing 3 into 2 is an incorrect method.
The fraction 3 over 2 actually means dividing 2 into 3.  You should get 1.5 for the fraction 3 over 2.
In general, the fraction a over b means dividing b *into* a, or equivalently dividing a *by* b.

Have a blessed, wonderful day!

Question 5

What's BEDMAS?

Accepted Answer

BEDMAS is an acronym like PEMDAS to help you remember the rules for order of operations.  The rules don't change.

Question 6

can somebody help me Evaluate 3/2 y - 3 +5/3 z  when y=4 and z=3 like im just lost

Accepted Answer

3/2y-3+5/3z y=4 z=3
3/2*4/1-3+5/3*3/1
12/2-3+15/3
6-3+5=8
||I was thinking it is solved this way||

Question 7

How is  practice number 2 solved?

Accepted Answer

1)  Replace each variable with its given value.
13-0.5(10)+6(1/2)

2) Follow order of operations rules (PEMDAS)
-- Multiply:  13-5+3
-- Add & subtract: 13-5+3 = 8+3 = 11

Hope this helps.

Question 8

I am a bit stuck. how do we do 3/2 • 4 and 5/3 • 3 
? Please help!

Accepted Answer

Several ways to do it, 3/2*4/1=3*4/2=12/2=6 or 3*4/2=3*2=6.

Question 9

How do i multiply 3/2 times 4

Accepted Answer

Change 4 into a fraction: 4/1
To multiply fractions, you multiply numerator to numerator and denominator to denominator.
3/2 * 4/1 = (3*4)/(2*1) = 12/2
Then, reduce the fraction to 6

Hope this helps.
FYI - You may want to get more practice working with fractions.  The lessons from here assume you know how to work with them.

Question 10

Why isn’t the answer tho the first “let’s practice” problem 14? I’ve went back to check if any mistakes had occurred but I found 0. Why isn’t it 14?

Accepted Answer

Replace each variable with their given value:
3/2(4) - 3 + 5/3(3)
Follow order of operations rules
Multiple: 12/2 - 3 + 15/3
Divide: 6 - 3 + 5
Add/subtract from left to right:
6-3+5 = 3+5 = 8

To get to 14, you must have added the 3 instead of subtracting it.

Hope this helps.

Course: 6th grade > Unit 6

Evaluating expressions with two variables: fractions & decimals

Let's study another example.

Now, let's practice

Want to join the conversation?