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avatar+3502 

2(r+2) + 5(1+5r)=63

Also this one that i'm stuck on

-30+7b=4(1+6b)

 Aug 18, 2015

Best Answer 

 #5
avatar+118587 
+10

Hi Zegroes  

 

2(r+2) + 5(1+5r)=63

2r+4    + 5+25r   =63

2r+25r   +4+ 5   =63

27r       +9          =63

                   27r  = 54

                    r    =  54/27

                    r    =  2

 

Also this one that i'm stuck on

-30+7b       =   4(1+6b)

-30+7b      =   4   +  24b

-30+7b-4   =   4   +  24b-4

-34 +7b      =   24b

-34 +7b -7b =   24b-7b

-34             =  17b

-34/17        =  17b/17

-2               =  b

             b =  -2

 Aug 18, 2015
 #1
avatar+2972 
+10

Problem #1:

$${\mathtt{2}}{\mathtt{\,\times\,}}\left({\mathtt{r}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2}}\right){\mathtt{\,\small\textbf+\,}}{\mathtt{5}}{\mathtt{\,\times\,}}\left({\mathtt{1}}{\mathtt{\,\small\textbf+\,}}{\mathtt{5}}{\mathtt{\,\times\,}}{\mathtt{r}}\right) = {\mathtt{63}}$$

2*r=2r

2*2=4

5*1=5

5*5r=25r

2r+4+5+25r=63

2r+25r=27r

4+5=9

$${\mathtt{27}}{\mathtt{\,\times\,}}{\mathtt{r}}{\mathtt{\,\small\textbf+\,}}{\mathtt{9}} = {\mathtt{63}}$$

$${\mathtt{63}}{\mathtt{\,-\,}}{\mathtt{9}} = {\mathtt{54}}$$

$${\mathtt{27}}{\mathtt{\,\times\,}}{\mathtt{r}} = {\mathtt{54}}$$

54/27 and 27/27= 2

$${\mathtt{R}} = {\mathtt{2}}$$

 Aug 18, 2015
 #2
avatar
+10

Reduce[2 (2 + r) + 5 (1 + 5 r) = 63, r]

4+2r+5+25r=63

9+27r=63

27r=63-9=54

r=54/27=2

 Aug 18, 2015
 #3
avatar+2972 
+10

Problem #2:

im guessing this is simplification 

-30+7b=4(1+6b)

4*1=4

4*6b=24b

-30+7b=4+24b

 Aug 18, 2015
 #4
avatar
+10

Reduce[-30 + 7 b = 4 (1 + 6 b), b]

-30+7b=4+24b

-30-4=24b-7b

-34=17

b=-34/17=-2

 Aug 18, 2015
 #5
avatar+118587 
+10
Best Answer

Hi Zegroes  

 

2(r+2) + 5(1+5r)=63

2r+4    + 5+25r   =63

2r+25r   +4+ 5   =63

27r       +9          =63

                   27r  = 54

                    r    =  54/27

                    r    =  2

 

Also this one that i'm stuck on

-30+7b       =   4(1+6b)

-30+7b      =   4   +  24b

-30+7b-4   =   4   +  24b-4

-34 +7b      =   24b

-34 +7b -7b =   24b-7b

-34             =  17b

-34/17        =  17b/17

-2               =  b

             b =  -2

Melody Aug 18, 2015

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