Working with square roots

[KimS]

I am trying to solve this equation:

3 * sqrrt(x+4) - 5 = 8

I am thinking that the order of operations is : square, *1/3, -4, +5, but when I check my work I don't get a confirmation that what I've done is correct. Am I not understanding something?

 

[Deleted member 4993]

I am trying to solve this equation:

3 * sqrrt(x+4) - 5 = 8

I am thinking that the order of operations is : square, *1/3, -4, +5, but when I check my work I don't get a confirmation that what I've done is correct. Am I not understanding something?

\(\displaystyle 3\cdot \sqrt{x+4} \ - \ 5 \ = \ 8\)

\(\displaystyle 3\cdot \sqrt{x+4} \ = \ 13\)

\(\displaystyle \sqrt{x+4} \ = \ \frac{13}{3}\)

Now square both sides...

 

[KimS]

This would mean the order of operations is : +5, *1/3, ^2,-4, which doesn't seem to conform to PEMDAS.

 

[Deleted member 4993]

This would mean the order of operations is : +5, *1/3, ^2,-4, which doesn't seem to conform to PEMDAS.

PEMDAS is applicable for "simplifying" or "evaluating".

While "solving for unknown" - as in "isolating the unknown" - actually we go in the reverse direction ? SADMEP

 

[KimS]

Okay, thank you.