√(15+x) = 2x+3
take sqr for both side
15x+10=(2x+3)^2
15x+10=4x^2+9+2*2x*3
15x+10=4x^2+9+12x
4x^2-3x--1=0
solve it u will x=1,-1/4
C) is the answer
An educated guess is an hypothesis.
A statement of pure fact is probably not a theory because it's not an educated reason
