Answer:
a+b = 4[tex]\sqrt{3}[/tex]
Step-by-step explanation:
3(a + b)^2 = 81
(a + b)^2 = 27
a + b = sq rt 27
a + b = [tex]\sqrt{9}[/tex]· [tex]\sqrt{3}[/tex]
a + b = 3[tex]\sqrt{3}[/tex]
