Answer:
[tex]5\frac{1}{3}[/tex]
Step-by-step explanation:
[tex]\boxed{a^{2} -b^{2} = (a +b)(a -b)}[/tex]
9x² -9y²= 72
Factorise:
9(x² -y²)= 72
Divide both sides by 9:
x² -y²= 8
(x +y)(x -y)= 8
Given that x -y= 1.5,
(x +y)(1.5)= 8
Divide both sides by 1.5:
x +y= [tex]5\frac{1}{3}[/tex]
