SOLUTION: 1. Solve a) -3√ (2x+1) +5 = -4 Can you please help me out? Thanks so much in advance:) Can you please show the steps it would really help me understand:)

Algebra ->  Radicals -> SOLUTION: 1. Solve a) -3√ (2x+1) +5 = -4 Can you please help me out? Thanks so much in advance:) Can you please show the steps it would really help me understand:)      Log On


   



Question 752499: 1. Solve
a) -3√ (2x+1) +5 = -4
Can you please help me out? Thanks so much in advance:)
Can you please show the steps it would really help me understand:)

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!

  -3√2x+1 + 5 = -4

We want to isolate the radical term -3√2x+1 on the left.

So we add -5 to both sides to get rid of the +5 on the left

      -3√2x+1 = -9

We square both sides:

   (-3√2x+1)² = (-9)²

(-3)²(√2x+1)² = 81

      9(2x+1) = 81

        18x+9 = 81

          18x = 72

            x = 72%2F18

            x = 4 

We MUST ALWAYS check radical equations,
because when you square both sides of
an equation, you would get the same
equation whether what was squared was
positive or negative.  So you may get
phony solutions, called "extraneous
solutions". 
 
  -3√2x+1 + 5 = -4

-3√2(4)+1 + 5 = -4

   -3√8+1 + 5 = -4

     -3√9 + 5 = -4

    -3(3) + 5 = -4

       -9 + 5 = -4

           -4 = -4

So it checks.  The solution is 4

Edwin