Math Question?

Question

Im working on combinding like terms

heres the problem:

3 (r - 1 ) - 4r + 5

Supposeably the answer is - r + 2

How can you show your work?
Can you explain the steps?
Thanks

Answer 1

just combine like terms

3(r-1) - 4r + 5
3r - 3 -4r +5
3r - 4r - 3 +5
-r + 2

Answer 2

Have you heard of the distibutive proberty?
Well first you distribute the three to the r and 1 so you have (3r-1)-4r+5
Then you do the ( ) and you get r
So roght now you have r-4r+5
okay well you want to change the - to a plus so you have r+4r+5 so then you have 5r+5 then you get 10r
Ask you teacher about the distributive property, PEMDAS, and LCR
Here is what they are if she can't tell you copy this if she doens't know cuz i will give you extras and examples
Same sign Take
Add and Sign
Different Of
Subtract Larger 5+(-6)= -1

Leave
Change LC R
Reverse -10+(7)=-17 originally -10-(-7)=

P- ( and ) (1+2) 5^2 / 5 + 1 - 2
E- x^y 3 x 5^2 / 5 + 1 - 2
M/D- x and / 3 x 25 /5 + 1 - 2
A/S- + and - 75 / 5 + 1 - 2
15 + 1 - 2
16 - 2
14
Multiply
Add 10^5
Divide ------- = 1^2
Subtract 9^3x9^2= 81^5 10^3

Communitive Property of + and x
1+2=2+1 2x3=3x2

Associative Property of +
(1+2)+3= 1+(2+3)

Additive Identnity
5+0=5

Multiplicative Identnity x1
1x7=7

Mulitplicative Property or 0
3x0=0

Thats it but talk to your techer about it and if you look at my 360 i may put mor throughout the school year.

Good luck

Answer 3

What you are doing is simplifying. To do this, you must first remove the brackets by multiplying everything in the brackets by 3. So that is r times 3 and 1 times three. Then it is simply subtraction (3r-4r and 5-3). Here is the full working:

3(r-1) - 4r + 5
3r - 3 - 4r + 5
-r + 2


Presumably this equals something? Usually equations like this are given the form:
n=-r+2 (where n is any number)
or
x=-r+2 (where you don't know what x is.)

Answer 4

First you distribute the 3 to the r and the -1. In other words, you multiply the r by 3 adn the -1 by 3. You should get this:

3r-3-4r+5

Then you combine like terms. The 3r and the -4r are the like terms, for they each have the same variable. Once you combine them, you should get this:

-r-3+5

There are two more like terms in this equation. -3 and 5. Of course, you combine them. Then you end up with this:

-r+2

You can't go any further than this, so this is your answer. If you want to know what method I used, I used the order of operations. It works like this: PEMDAS (Parenthesis, Exponents, Multiply, Divide, Add, Subtract. I also split up the equation. First, you do work in the parenthesis. I separated 3(r-1) from the equation, and used the Distributive Property. Then I just followed the order of operations. Exponents came next. There were none, so I went to multiply. That kinda went with the disributive property. Then Divide, nothing to divide, so skip that. Then Add. When I combined like terms, that was addition. If this last paragraph confused you, ignore it. Just use my procedure that I did to solve before this paragraph. Hope I helped and didn't confuse you!

Answer 5

3(r -1) - 4r + 5 Distibutive property
3r - 3 - 4r + 5 Combine Like terms
-r +2

Does that help?

Answer 6

Multiply out the 3 (r -1) so you get:
3r - 3 - 4r + 5
and then simplify:
3r - 4r = -1r
-3 + 5 = 2

so you have -r +2

Answer 7

kay, brackets mean multiply, right? so we multiply the number outside the bracket by EVERYTHING inside the bracket.
3(r-1)-4r+5
3r-3-4r+5
ur grouping like terms, so put all the expressions that have an r together, and put all the regular numbers together.
3r-4r-3+5
-r+2

Answer 8

3r -3 -4r + 5 (distribute)

-r + 2 (group like terms)

Answer 9

3(r-1)-4r+5
do parenthesis first and get
3r-3-4r+5
take the sign in front and move your terms next to each other and get
3r-4r-3+5
then add and subtract to get your
-r+2

Answer 10

3r-3-4r+5
=-r+2