SOLUTION: Solve. (Be sure to check your solution): sqrt(2y + 7) + 4 = y

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Solve. (Be sure to check your solution): sqrt(2y + 7) + 4 = y       Log On


   

Question 179712: Solve. (Be sure to check your solution):
sqrt(2y + 7) + 4 = y

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%282y%2B7%29%2B4=y
sqrt%282y%2B7%29%2B4-4=y-4
sqrt%282y%2B7%29=y-4
2y%2B7=%28y-4%29%5E2
2y%2B7=y%5E2-8y%2B16
y%5E2-10y%2B9=0
%28y-9%29%28y-1%29=0
Two solutions:
x-9=0
x=9
.
.
.
x-1=0
x=1
Let's check both answers.
sqrt%282y%2B7%29%2B4=y
sqrt%282%289%29%2B7%29%2B4=9
sqrt%2818%2B7%29%2B4=9
sqrt%2825%29%2B4=9
5%2B4=9
9=9
.
.
.
sqrt%282%281%29%2B7%29%2B4=1
sqrt%282%2B7%29%2B4=1
sqrt%289%29%2B4=1
-3%2B4=1
1=1