Please solve for y, where y is a real number Sq.Rt.7-y=y-1

Question

Sq.Rt.7-y=y-1

 

Thanks

Answer 1

√(7-y) = y-1

 

Square both sides to get 7-y = y²-2y+1

 

                                         0 = y²-y-6

 

                                         0 = (y-3)(y+2)

 

y = 3 or y = -2

 

Check:  if y = 3, then √(7-y) = 2 = y-1

 

            if y = -2, then √(7-y) = 3 ≠ y-1

 

The only solution is 3.