Question

How do you solve `2b^2 = 162`?

Answer 1

`b=9 or b=-9`

Explanation:

Here,

`2b^2=162`

Dividing both sides by `2`

`(2b^2)/2=162/2`

`:.b^2=81`

`:.b^2=9^2`

`:.b^2-9^2=0`

`:.(b-9)(b+9)=0to[because x^2-y^2=(x-y)(x+y)]`

`:.b-9=0 or b+9=0`

`:.b=9 or b=-9`

Answer 2

`b=+-9`

Explanation:

`"divide both sides by 2"`

`b^2=162/2=81`

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

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

`rArrb=+-9`

Answer 3

`b=+-9`

Explanation:

We want to isolate `b`. Right now it is being multiplied by `2`, so we can do the inverse, divide by `2` to get

`b^2=81`

Next, we can take the inverse of squaring, which is the square root (of both sides) to get

`b=+-9`

Hope this helps!