Hey guys, sry if this question is really amateur but I've been confused by this for a while.

I've been reading about pot odds and has been confused about different between using hand odds and hand equity.

Ex: (hero) 4h7h

Flop: AhJcTh disregarding what opponent and lets just assume making a flush gives us the winning hand.

From my research it explains calculating odds in two different ways

1.) Hand odd.

You have 2 hearts. Two more hearts fall on the flop. There are now 47 unseen cards. You have 9 outs (9 out of 13 unseen hearts remaining in the deck) to make your flush on the next card.
Divide 47 by 9 = 5.2
Subtract 1 = 4.2
There must be at least 4.2 bets in the pot for you to call a single bet.

2.) the multiply by 4 and 2 rules to calculate hand equity.

You have two hearts. Two more hearts fall on the flop, so you have 9 outs.
9 x 4 = 36, giving you 36% chance to hit your flush and your opponent a 64% chance to hold up and win with a pair.
64/36 is a little less than 2 to 1. Therefore, it would make sense to call bets slightly higher than half the pot size.

I understand the concept of both and should be both right? but what I'm confused about is why hand odd method req. us to have 4.2:1 to call on flop while hand equity only requires us to have 2:1 to call.

thanks.