In order to make b the subject of this equation, we must isolate it on the left side. We can do this by following these steps:
\(P = 2a+b\)
Subtract b from both sides
\(P - b = 2a+b-b\)
\(P-b=2a\)
Subtract P from both sides
\(P-b-P=2a-P\)
\(-b=2a-P\)
Now, we have isolated b, but it is negative. We can fix this by multiplying both sides of the equation by -1.
\(-(-b)=-(2a-P)\)
\(b=-2a+P\)
Which is your final answer.
\(b = -2a+P\).
Hope that helped! =)
