sqrt(q^2+7q+6)-q-3=0

Answer 1

√(q^2 + 7q + 6) = q+3
square both sides
q^2+7q+6 = q^2 + 6q + 9
q = 3

check: (in the original)
LS =√(9+21+6) -3 - 3
= √36 -3 - 3
= 6-3-3
=0
=RS

so x = 3