Question

Make b the subject of the formula P=2a+b

Answer 1

If you're trying to isolate b, then you can do the following:

P=2a+b
P-2a=b
b=P-2a

But I'm not sure if that's what it is asking you to do.

Answer 2

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! =)