SOLUTION: The sum of a number and twice its square is 105. Find the number.

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Question 350775: The sum of a number and twice its square is 105. Find the number.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let the number be x
x+2x^2=105
2x^2+x-105 =0
2x^2+15x-14x-105
x(2x+15)-7(2x+15)=0
(x-7)(2x+15)=0
x= 7 OR x=-7.5