Answer:
7/12
Step-by-step explanation:
30+40+50=120
120 buttons in total
30+40=70
70 buttons that aren't white
70/120 is the probability
Simplify that to 7/12
Due to PEMDAS, you want to start with multiplying the parenthesis. I will group it first so that you can see the grouping easier.
-4(-2) + 3(4) + 3(-4) - 5(4)
Now we multiply the terms together.
-8 + 12 - 12 - 20
As you can see above, there is a positive 12 and a negative 12. These two will cancel out, leaving you with:
-8 - 20
Now you just combine the terms.
This results in a final answer of -28!
