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21 votes
21 votes
PLEASE i need help so badly asap

PLEASE i need help so badly asap-example-1
User Wbhuana
by
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1 Answer

12 votes
12 votes

Answer:

13

Explanation:

We can multiply both the whole equation by
c^2-7c-18. This is the LCM of all of the denominators. Notice that when
c^2-7c-18 is factored, we obtain
(c - 9)(c+2).

Step 1: Multiply Left Side by
c^2-7c-18


(5)/(c-9)*(c^2-7c-18)=(5)/(c-9)*(c-9)(c+2)=5(c+2)=5(c)+5(2)=5c+10

Step 2: Multiply Right Side by
c^2-7c-18

An easier approach is to multiply each individual fraction like so:


(5c-2)/(c^2-7c-18)*(c^2-7c-18)=5c-2


(3)/(c+2)*(c^2-7c-18)=(3)/(c+2)*(c-9)(c+2)=3(c-9)=3c-27

Then, we add them:


5c-2+(3c-27)=5c-2+3c-27=8c-29

Therefore the whole equation is now:


5c+10=8c-29

Step 3: Solve for "c"

Subtract 5c from both sides:


10=3c-29

Add 29 to both sides:


39=3c

Divide both sides by 3


c=13

Step 4: Plug 13 in for "c" to check our work


(5)/(13-9)=(5(13)-2)/(169-91-14)+(3)/(13+2)\\\\(5)/(4)=(63)/(60)+(3)/(15)\\\\(5)/(4)=(21)/(20)+(1)/(5)\\\\(5)/(4)=(21)/(20)+(1)/(5)\\\\(5)/(4)=(21)/(20)+(4)/(20)\\\\(5)/(4)=(25)/(20)\\\\(5)/(4)=(5)/(4)\Rightarrow Correct!

Therefore,

c = 13

User BigBoss
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