Hi all just wondering if someone can help me understand this little bit so we have

14a + 2(3b +5) = 30 need to make a the subject

So

30 - 2(3b + 5) = 14 a /2 to get

7a = 15 - (3b + 5) expand brackets to get

7a = 15 - 3b - 5 which I get now this is where I am confused when we group these like terms we get

7a = -3b + 10

What I can’t figure out is why we don’t get 10 - 3b or

-3b - 10

Appreciate any help you guys can give I’m close just can’t wrap my head around this little part