SOLUTION: 5+ROOT(a+7)=a or 5+√(a + 7)=a please show all your work, and here is what i did 5+√(a + 7)=a 5=√(a + 7)+a 25=a+7+2a 25=2a+a+7 2a+a-18 but thats wron

Algebra ->  Radicals -> SOLUTION: 5+ROOT(a+7)=a or 5+√(a + 7)=a please show all your work, and here is what i did 5+√(a + 7)=a 5=√(a + 7)+a 25=a+7+2a 25=2a+a+7 2a+a-18 but thats wron      Log On


   

Question 618114: 5+ROOT(a+7)=a
or
5+√(a + 7)=a
please show all your work, and here is what i did

5+√(a + 7)=a
5=√(a + 7)+a
25=a+7+2a
25=2a+a+7
2a+a-18
but thats wrong, where did i make a mistake and please work out this problem thank you
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, 

 +5+%2B+sqrt%28a%2B7%29+=+a    |||Need to isolate the radical on one side the EQ

 ++sqrt%28a%2B7%29+=+a+-+5

 ++%28a%2B7%29+=+%28a+-+5%29%5E2

 ++%28a%2B7%29+=+a%5E2-+10a+%2B+25

 ++0=+a%5E2-+11a+%2B+18

 a^2- 11a + 18 = 0

factoring:

 (a-9)(a-2) = 0

 (a-9)= 0

    a = 9

 (a-2) = 0

    a = 2