Question

Xiao's teacher asked him to rewrite the sum 60+ 90 as the product of the GFC of the two numbers and a sum. Xiao wrote 3(20+30). What mistake did Xiao make? How should he have written the sum?

Answer 1

The greatest common factor here is not 3, it's 30.
so it should be 30(2+3)

hopefully this helps!