total marbles: 2+3+7 = 12
add blue and yellow 2+3=5
7 marbles aren't blue or yellow
probability = 7/12 marble is not one of those
Fractions they are easy REALLY!!
X-5+5x-12=25
x+5x=25+5+12
6x=42
x=42/6
x=7
Answer: The formula is (b1 + b2)h+PH
Step-by-step explanation:
