Question

Pls help me pls pls pls help me. thanks. ​

Answer 1

`7ab`

Hope it helped.

Answer 2

Explanation:

21ab² = 3 * 7 * a * b²

28abc = 2 * 2 * 7 * a * b * c

42abc² = 2 * 3 * 7 * a * b * c

HCF = 7ab