SOLUTION: Solve 9x^2+6x+1=64 I think you first subtract 1 form each side which leaves you 9x^2+6x=63. You then find what term a, b, and c is. Then you use the quadratic formula. and when I d

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: Solve 9x^2+6x+1=64 I think you first subtract 1 form each side which leaves you 9x^2+6x=63. You then find what term a, b, and c is. Then you use the quadratic formula. and when I d      Log On


   

Question 243623: Solve 9x^2+6x+1=64 I think you first subtract 1 form each side which leaves you 9x^2+6x=63. You then find what term a, b, and c is. Then you use the quadratic formula. and when I did it, it becomes the suare root of negative 531, but I know it's not suupose to be negative. Can you help me?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

9x%5E2%2B6x%2B1=64 Start with the given equation.


9x%5E2%2B6x%2B1-64=0 Subtract 64 from both sides.


9x%5E2%2B6x-63=0 Combine like terms.


Notice that the quadratic 9x%5E2%2B6x-63 is in the form of Ax%5E2%2BBx%2BC where A=9, B=6, and C=-63


Let's use the quadratic formula to solve for "x":


x+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29 Start with the quadratic formula


x+=+%28-%286%29+%2B-+sqrt%28+%286%29%5E2-4%289%29%28-63%29+%29%29%2F%282%289%29%29 Plug in A=9, B=6, and C=-63


x+=+%28-6+%2B-+sqrt%28+36-4%289%29%28-63%29+%29%29%2F%282%289%29%29 Square 6 to get 36.


x+=+%28-6+%2B-+sqrt%28+36--2268+%29%29%2F%282%289%29%29 Multiply 4%289%29%28-63%29 to get -2268


x+=+%28-6+%2B-+sqrt%28+36%2B2268+%29%29%2F%282%289%29%29 Rewrite sqrt%2836--2268%29 as sqrt%2836%2B2268%29


x+=+%28-6+%2B-+sqrt%28+2304+%29%29%2F%282%289%29%29 Add 36 to 2268 to get 2304


x+=+%28-6+%2B-+sqrt%28+2304+%29%29%2F%2818%29 Multiply 2 and 9 to get 18.


x+=+%28-6+%2B-+48%29%2F%2818%29 Take the square root of 2304 to get 48.


x+=+%28-6+%2B+48%29%2F%2818%29 or x+=+%28-6+-+48%29%2F%2818%29 Break up the expression.


x+=+%2842%29%2F%2818%29 or x+=++%28-54%29%2F%2818%29 Combine like terms.


x+=+7%2F3 or x+=+-3 Simplify.


So the solutions are x+=+7%2F3 or x+=+-3