Help pleasee i urgently need help pleasee

3

Step-by-step explanation:

Pretend A is just three, B is just 4, and C is just 5.

3(3)-4(4)+2(5)

9-4(4)+2(5)

9-16+2(5)

9-16+10

-7+10

3

+3

Explanation: Start by plugging in the appropriate values for a, b, and c.

You might also want to change the -4b

to plus a negative 4b to avoid confusion.

Also, use parenthses when substituting numbers in for variables.

So we have 3(3) + -4(4) + 2(5).

Once you have plugged in your numbers, first multiply,

and then add from left to right.

So we have (9) + (-16) + (10).

Now add to get (-7) + (10) which is +3.

the correct is answer is a 9-sided polygon!