SOLUTION: 2. x2 – 2x – 11 = 0 Use the Quadratic Formula to solve each equation.

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Question 375527: 2. x2 – 2x – 11 = 0 Use the Quadratic Formula to solve each equation.
Found 2 solutions by jim_thompson5910, ewatrrr:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2-2x-11=0 Start with the given equation.


Notice that the quadratic x%5E2-2x-11 is in the form of Ax%5E2%2BBx%2BC where A=1, B=-2, and C=-11


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-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Plug in A=1, B=-2, and C=-11


x+=+%282+%2B-+sqrt%28+%28-2%29%5E2-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Negate -2 to get 2.


x+=+%282+%2B-+sqrt%28+4-4%281%29%28-11%29+%29%29%2F%282%281%29%29 Square -2 to get 4.


x+=+%282+%2B-+sqrt%28+4--44+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-11%29 to get -44


x+=+%282+%2B-+sqrt%28+4%2B44+%29%29%2F%282%281%29%29 Rewrite sqrt%284--44%29 as sqrt%284%2B44%29


x+=+%282+%2B-+sqrt%28+48+%29%29%2F%282%281%29%29 Add 4 to 44 to get 48


x+=+%282+%2B-+sqrt%28+48+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%282+%2B-+4%2Asqrt%283%29%29%2F%282%29 Simplify the square root (note: If you need help with simplifying square roots, check out this solver)


x+=+%282%29%2F%282%29+%2B-+%284%2Asqrt%283%29%29%2F%282%29 Break up the fraction.


x+=+1+%2B-+2%2Asqrt%283%29 Reduce.


x+=+1%2B2%2Asqrt%283%29 or x+=+1-2%2Asqrt%283%29 Break up the expression.


So the solutions are x+=+1%2B2%2Asqrt%283%29 or x+=+1-2%2Asqrt%283%29


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Use the Quadratic Formula to solve

x^2 – 2x – 11 = 0 

x+=+%282+%2B-+sqrt%284+%2B+44%29%29%2F%282%29+

x+=+%282+%2B-+sqrt%2848%29%29%2F%282%29+

x+=+%282+%2B-+4%2Asqrt%283%29%29%2F%282%29+

x+=+%281+%2B-+2%2Asqrt%283%29%29+

x = 4.464

x = -2.464