Question

How do you evaluate `a^2 - (3c)` if `a = 9, b= 3`, and `c = 1/3`?

Answer 1

You can disregard `b`, because you can see there is no reason to use `b` in an equation that doesn't contain `b`.

Just plug in the numbers that are defined for you.

`color(blue)(a^2 - 3c)`

`= (9)^2 - 3c`

`= (9)^2 - 3(1/3)`

`= 9*9 - cancel(3)*1/cancel(3)`

`= 9*3*3 - 1`

`= 27*3 - 1`

`= 81 - 1`

`= color(blue)(80)`