2=sq root of 2U+7 - sq root of U
calculating for U:
2=sqrt(2U+7)-sqrt(U)
2+sqrt(U)=sqrt(2U+7)
square both sides:
4 + 4*sqrt(U)+ U = 2U+7
transpose all terms not containing squareroot on one side of equation:
4*sqrt(U) = 2U + 7 -4 - U
4*sqrt(U) = U + 3
square both sides:
16U = U^2 + 6U + 9
U^2 -10U + 9 = 0
(U-9)(U-1) = 0
U = 9 and U = 1
*then check if there is extraneous root by substituting back to original equation,,
*since there is no extraneous root,
U = 9 and U = 1
so there,, :)