Question 49777
{{{( ((sqrt(2y+7)) + 4)) = y)))) }}}
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{{{( ((sqrt(2y+7)) + 4 - 4)) = y - 4)))) }}} [Isolate the radical to one side]
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{{{( ((sqrt(2y+7)))) = y - 4)))) }}} 
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{{{( (((sqrt(2y+7)))))^2 = ((y - 4))^2)))) }}} [Square both sides]
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2y+7 = (y - 4)(y - 4) [Multiply by using the FOIL method]
2y+7=y^2-8y+16[Set the equaion equal to zero by getting all of the terms to one side of the equation]
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2y+7-7=y^2-7-8y+16 
2y=y^2-8y+9
2y-2y=y^2-8y-2y+9
0=y^2-10y+9 [Factor]
0 = (y-9)(y-1) [solve for y]
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0=y-9
y=9
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0=y-1
y=1
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y=9 or y=1 [Final answers]
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Check by plugging the values of "y" back into the original equatin.