SOLUTION: I need help in solving it I see the steps but dont understand them. x squared plus 7x equals negative twelve

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Question 610883: I need help in solving it I see the steps but dont understand them. x squared plus 7x equals negative twelve
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2%2B7x=-12 Start with the given equation.


x%5E2%2B7x%2B12=0 Get every term to the left side.


Notice that the quadratic x%5E2%2B7x%2B12 is in the form of Ax%5E2%2BBx%2BC where A=1, B=7, and C=12


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-%287%29+%2B-+sqrt%28+%287%29%5E2-4%281%29%2812%29+%29%29%2F%282%281%29%29 Plug in A=1, B=7, and C=12


x+=+%28-7+%2B-+sqrt%28+49-4%281%29%2812%29+%29%29%2F%282%281%29%29 Square 7 to get 49.


x+=+%28-7+%2B-+sqrt%28+49-48+%29%29%2F%282%281%29%29 Multiply 4%281%29%2812%29 to get 48


x+=+%28-7+%2B-+sqrt%28+1+%29%29%2F%282%281%29%29 Subtract 48 from 49 to get 1


x+=+%28-7+%2B-+sqrt%28+1+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-7+%2B-+1%29%2F%282%29 Take the square root of 1 to get 1.


x+=+%28-7+%2B+1%29%2F%282%29 or x+=+%28-7+-+1%29%2F%282%29 Break up the expression.


x+=+%28-6%29%2F%282%29 or x+=++%28-8%29%2F%282%29 Combine like terms.


x+=+-3 or x+=+-4 Simplify.


So the solutions are x+=+-3 or x+=+-4


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