Arthur D. answered 04/16/17
Tutor
4.9
(286)
Forty Year Educator: Classroom, Summer School, Substitute, Tutor
√(p+7)=√(2p)+1
square both sides
p+7=2p+2√(2p)+1
p+7-2p-1=2√(2p)
-p+6=2√(2p)
square both sides again
P^2-12p+36=8p
p^2-12p+36-8p=0
p^2-20p+36=0
factor
(p-2)(p-18)=0
p-2=0
p=2
p-18=0
p=18
there is only one solution: p=2 (answer)
p=18 gives a false equation when you replace p by 18 in the original equation