Question

How do you solve `4b^2+2=326`?

Answer 1

`b=+-9`

Explanation:

`"subtract 2 from both sides of the equation"`

`rArr4b^2=324`

`"divide both sides by 4"`

`rArrb^2=81`

`color(blue)"take the square root of both sides"`

`rArrb=+-sqrt81larrcolor(blue)"note plus or minus"`

`rArrb=+-9`

Answer 2

`b=pm9`

Explanation:

As with any equation, we want to get the unknown value we are trying to work out on its own. Therefore we need to get rid of the `+2`, and by doing this we do the opposite to both sides, which is to `-2`:

`4b^2+2=326 -> 4b^2=324`

As we would like to have B on its own, we need to get rid of the `4` in front, and by doing this we do the opposite to both sides, which is to `/4`

`4b^2=324 -> b^2=81`

Now we want b on its own again, we do not want the `^2` added on, therefore, we do the opposite which is to `sqrt`:

`b^2=81 -> b=pmsqrt81`

`-> b=pm9`

Always remember the `pm`, and this is our final answer as it cannot be simplified further.