Math
posted by Lynn on .
Find the value of x.
The area of a rectangle = 105
The length is 2x+1
Width is x
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I tried solving it :
Arec = l x w
105 = (2x+1)x
105 = 2x^2 + x
0= 2x^2 + x  105
This is where I get stuck on...

quadratic equation
x = [ 1 +/ sqrt (1+840)]/4
= [ 1 +/ 29 ]/4
= 28/4 forget negative solution
= 7
or
(x  7) (2x + 15) = 0