SOLUTION: x^2+17x+42=0

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Question 560574: x^2+17x+42=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
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x%5E2%2B17x%2B42=0 Start with the given equation.


Notice that the quadratic x%5E2%2B17x%2B42 is in the form of Ax%5E2%2BBx%2BC where A=1, B=17, and C=42


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-%2817%29+%2B-+sqrt%28+%2817%29%5E2-4%281%29%2842%29+%29%29%2F%282%281%29%29 Plug in A=1, B=17, and C=42


x+=+%28-17+%2B-+sqrt%28+289-4%281%29%2842%29+%29%29%2F%282%281%29%29 Square 17 to get 289.


x+=+%28-17+%2B-+sqrt%28+289-168+%29%29%2F%282%281%29%29 Multiply 4%281%29%2842%29 to get 168


x+=+%28-17+%2B-+sqrt%28+121+%29%29%2F%282%281%29%29 Subtract 168 from 289 to get 121


x+=+%28-17+%2B-+sqrt%28+121+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-17+%2B-+11%29%2F%282%29 Take the square root of 121 to get 11.


x+=+%28-17+%2B+11%29%2F%282%29 or x+=+%28-17+-+11%29%2F%282%29 Break up the expression.


x+=+%28-6%29%2F%282%29 or x+=++%28-28%29%2F%282%29 Combine like terms.


x+=+-3 or x+=+-14 Simplify.


So the solutions are x+=+-3 or x+=+-14
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