SOLUTION: 2x^2 +16= -12x Please help I am so confused

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: 2x^2 +16= -12x Please help I am so confused      Log On


   

Question 263091: 2x^2 +16= -12x
Please help I am so confused
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

2x%5E2%2B16=-12x Start with the given equation.


2x%5E2%2B12x%2B16=0 Add 12x to both sides.


Notice that the quadratic 2x%5E2%2B12x%2B16 is in the form of Ax%5E2%2BBx%2BC where A=2, B=12, and C=16


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-%2812%29+%2B-+sqrt%28+%2812%29%5E2-4%282%29%2816%29+%29%29%2F%282%282%29%29 Plug in A=2, B=12, and C=16


x+=+%28-12+%2B-+sqrt%28+144-4%282%29%2816%29+%29%29%2F%282%282%29%29 Square 12 to get 144.


x+=+%28-12+%2B-+sqrt%28+144-128+%29%29%2F%282%282%29%29 Multiply 4%282%29%2816%29 to get 128


x+=+%28-12+%2B-+sqrt%28+16+%29%29%2F%282%282%29%29 Subtract 128 from 144 to get 16


x+=+%28-12+%2B-+sqrt%28+16+%29%29%2F%284%29 Multiply 2 and 2 to get 4.


x+=+%28-12+%2B-+4%29%2F%284%29 Take the square root of 16 to get 4.


x+=+%28-12+%2B+4%29%2F%284%29 or x+=+%28-12+-+4%29%2F%284%29 Break up the expression.


x+=+%28-8%29%2F%284%29 or x+=++%28-16%29%2F%284%29 Combine like terms.


x+=+-2 or x+=+-4 Simplify.


So the solutions are x+=+-2 or x+=+-4