Answer:
Angelina should buy 9 packs of pens and 8 packs of pencils.
Step-by-step explanation:
Each pack of pens = 8 pens
Each pack of pencils = 9 pencils.
Also we know that, Commutative Property of Multiplication states that
a x b = b x a for any two numbers a and b.
So, 8 x 9 = 72 = 9 x 8
Hence, she should buy 9 packs of pens, so she will have 9 x 8 = 72 pens.
And she should buy 8 packs of pencils, she will have 8 x 9 = 72 pencils.
