SOLUTION: Hi, can you please help me? Ive tried this problem 9 times...and I keep getting it wrong... Thank you sooo much for your help! i hope you can help me... it would be soo appreciate

Algebra ->  Finance -> SOLUTION: Hi, can you please help me? Ive tried this problem 9 times...and I keep getting it wrong... Thank you sooo much for your help! i hope you can help me... it would be soo appreciate      Log On


   

Question 499121: Hi, can you please help me? Ive tried this problem 9 times...and I keep getting it wrong...
Thank you sooo much for your help! i hope you can help me... it would be soo appreciated! :)
Find all real solutions of the equation. or tell if there is NO REAL SOLUTION.
squareroot of: 9x + 64+8=x


Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%289x%2B64%2B8%29=x
sqrt%289x%2B72%29=x
Take the square
9x+72=x^2
x^2-9x-72=0
Find the roots of the equation by quadratic formula

a= 1 ,b= -9 c -72

b^2-4ac= 81 - 288
b^2-4ac= 369
sqrt%28%09369%09%29= 19.21
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=( 9 + 19.21 )/ 2
x1= 14.1
x2=( 9 -19.21 ) / 2
x2= -5.105