In:mi
2 = 30
x = 120
2/30=x/120
(Cross Multiply)
30x= 240
30x/30=240/30
X=8
Answer:

Step-by-step explanation:
Let x = number of books that Hannah donated
We know that the number of students is 150 and the total number of books is represented by b, we can write that as:
Average number of books donated by each student = 
Now we know that Hannah donated 3 times as much as the average. We can write that as:

Answer:
$4.12
Step-by-step explanation:
$26.78 / 6.5 gallons = $4.12 per gallon
(a + b)^3 = a^3 + 3a^2b + 3ab^2+ b^3
(a +(- b))^3 = (a-b)^2 = a^3 - 3a^2b + 3ab^2- b^3