SOLUTION: I cannot figure out the Pythagorean theorem when there is two variables and one regular number. I need to solve {{{x^2+3x^2=18^2}}}.I have(well I think) already between 5 2/3 and 5

Algebra ->  Pythagorean-theorem -> SOLUTION: I cannot figure out the Pythagorean theorem when there is two variables and one regular number. I need to solve {{{x^2+3x^2=18^2}}}.I have(well I think) already between 5 2/3 and 5      Log On


   

Question 123457This question is from textbook College Prepatory Mathematics 1
: I cannot figure out the Pythagorean theorem when there is two variables and one regular number. I need to solve x%5E2%2B3x%5E2=18%5E2.I have(well I think) already between 5 2/3 and 5.7. This question is from textbook College Prepatory Mathematics 1

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
solve x%5E2%2B3x%5E2=18%5E2
:
x^2 and 3x^2 are like terms, just add them together, square 18 to get 324
4x%5E2+=+324
Divide both sides by 4
x%5E2+=+324%2F4
x%5E2+=+81
x = sqrt%2881%29
x = 9
:
:
Check solution:
9^2 + 3(9^2) =
81 + 3(81) =
81 + 343 = 324, which is 18^2