I got y=7, I haven't done any algebra in a while so I'm probably wrong.
Edit: I did it wrong but somehow got the right answer ¯\_(ツ)_/¯ Here's what I did:
2(2y+7)=42
step 1: ignore the distributive property and GEMDAS like an idiot and factor out the 2
2y+7=21
step 2: subtract 7 from both sides
2y=14
step 3: divide both sides by 2
y=7
the way you're meant to do it is first distribute the 2 and get 4y+14=42 which when simplified like so is also 7:
subtract 14 from both sides 4y=28
divide both sides by 4. y=7