Two scenarios
You have a baby who will happily take a bottle at 7 months.
You have a baby that won't. I had two mix fed babies that went on bottle strike from 5.5 months right on time for me to go back to work. DD2 caved eventually but DD1 did not and wouldn't take anything milk or water so hydration was a big issue.
They will need circa 20oz a day or a minimum of 12 oz. This can be through food (mixed into weetabix for example) or via a bottle or bf.
So that's approx 2.5-3 8oz bottles a day. At 7 months they are likely to consume close to 4 with it dropping back as they take in more solids.
BF in the morning, and as soon as you get home before bedtime, with a botle of milk after naptime. In practice at 7 months, they often want a lot more than that with a short feed before the lunchtime nap or if a mealtime goes badly. If you have a baby who is not keen on a bottle, then you will need the carer to offer some formula at regular intervals during the day so the odd ounce goes down.
If you want to do Baby Led Weaning, then the baby will need to be on 5 full feeds a day as it's a slow start as far as I know. As my DD1 wouldn't take a bottle we had no choice but to start getting the solids into her. DD2 could have gone either way but we went with what we knew at that stage.
I dropped a feed a week with Dd1 [hard work deadline with extensive overseas travel as soon as I returned so had to quit bf entirely] and had issues.
With Dd2, I dropped one every 2 weeks and it was much more comfortable physically for me.
DD1 was an early teether and I comfort bf her a lot in the middle of the night. I think it did her no favours as it left her just about hydrated and well fed enough at the start of weaning to refuse a bottle or sippy cup. When I had to stop bf entirely, she was entrenched and there was months of watering down her food, yoghurt etc with milk to keep her on track.